triangles and lines – special right triangles there are two special right triangles : 30 – 60...

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Triangles and Lines – Special Right Triangles There are two special right triangles : 30 – 60 – 90 degree right triangle 45 – 45 – 90 degree right triangle

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Page 1: Triangles and Lines – Special Right Triangles There are two special right triangles : 30 – 60 – 90 degree right triangle 45 – 45 – 90 degree right triangle

Triangles and Lines – Special Right Triangles

There are two special right triangles :

30 – 60 – 90 degree right triangle

45 – 45 – 90 degree right triangle

Page 2: Triangles and Lines – Special Right Triangles There are two special right triangles : 30 – 60 – 90 degree right triangle 45 – 45 – 90 degree right triangle

Triangles and Lines – Special Right Triangles

There are two special right triangles :

30 – 60 – 90 degree right triangle

45 – 45 – 90 degree right triangle

30

60

In a 30 – 60 – 90 right triangle, the hypotenuse is two times longer than the shortest leg

x

2x

Page 3: Triangles and Lines – Special Right Triangles There are two special right triangles : 30 – 60 – 90 degree right triangle 45 – 45 – 90 degree right triangle

Triangles and Lines – Special Right Triangles

There are two special right triangles :

30 – 60 – 90 degree right triangle

45 – 45 – 90 degree right triangle

30

60

In a 30 – 60 – 90 right triangle, the hypotenuse is two times longer than the shortest leg

Using the Pythagorean theorem, we find the third side is square root of three times bigger than the shortest side.

x

2x3x

Page 4: Triangles and Lines – Special Right Triangles There are two special right triangles : 30 – 60 – 90 degree right triangle 45 – 45 – 90 degree right triangle

Triangles and Lines – Special Right Triangles

There are two special right triangles :

30 – 60 – 90 degree right triangle

45 – 45 – 90 degree right triangle

30

60

Example # 1 : Find the other two sides if the hypotenuse = 10

x

2x =103x

In a 30 – 60 – 90 right triangle, the hypotenuse is two times longer than the shortest leg

Using the Pythagorean theorem, we find the third side is square root of three times bigger than the shortest side.

Page 5: Triangles and Lines – Special Right Triangles There are two special right triangles : 30 – 60 – 90 degree right triangle 45 – 45 – 90 degree right triangle

Triangles and Lines – Special Right Triangles

There are two special right triangles :

30 – 60 – 90 degree right triangle

45 – 45 – 90 degree right triangle

30

60

Example # 1 : Find the other two sides if the hypotenuse = 10

x = 5

3x

In a 30 – 60 – 90 right triangle, the hypotenuse is two times longer than the shortest leg

Using the Pythagorean theorem, we find the third side is square root of three times bigger than the shortest side.

52

10

x

x

2x =10

Page 6: Triangles and Lines – Special Right Triangles There are two special right triangles : 30 – 60 – 90 degree right triangle 45 – 45 – 90 degree right triangle

Triangles and Lines – Special Right Triangles

There are two special right triangles :

30 – 60 – 90 degree right triangle

45 – 45 – 90 degree right triangle

30

60

Example # 1 : Find the other two sides if the hypotenuse = 10

x = 5

2x =103x

In a 30 – 60 – 90 right triangle, the hypotenuse is two times longer than the shortest leg

Using the Pythagorean theorem, we find the third side is square root of three times bigger than the shortest side.

52

10

x

x

35

35 is side Third

Page 7: Triangles and Lines – Special Right Triangles There are two special right triangles : 30 – 60 – 90 degree right triangle 45 – 45 – 90 degree right triangle

Triangles and Lines – Special Right Triangles

There are two special right triangles :

30 – 60 – 90 degree right triangle

45 – 45 – 90 degree right triangle

30

60

Example # 2 : Find the other two sides if the shortest side = 8

x = 8

2x3x

In a 30 – 60 – 90 right triangle, the hypotenuse is two times longer than the shortest leg

Using the Pythagorean theorem, we find the third side is square root of three times bigger than the shortest side.

Page 8: Triangles and Lines – Special Right Triangles There are two special right triangles : 30 – 60 – 90 degree right triangle 45 – 45 – 90 degree right triangle

Triangles and Lines – Special Right Triangles

There are two special right triangles :

30 – 60 – 90 degree right triangle

45 – 45 – 90 degree right triangle

30

60

Example # 2 : Find the other two sides if the shortest side = 8

x = 8

2x =163x

In a 30 – 60 – 90 right triangle, the hypotenuse is two times longer than the shortest leg

Using the Pythagorean theorem, we find the third side is square root of three times bigger than the shortest side.

16)8(2

Page 9: Triangles and Lines – Special Right Triangles There are two special right triangles : 30 – 60 – 90 degree right triangle 45 – 45 – 90 degree right triangle

Triangles and Lines – Special Right Triangles

There are two special right triangles :

30 – 60 – 90 degree right triangle

45 – 45 – 90 degree right triangle

30

60

Example # 2 : Find the other two sides if the shortest side = 8

x = 8

2x =163x

In a 30 – 60 – 90 right triangle, the hypotenuse is two times longer than the shortest leg

Using the Pythagorean theorem, we find the third side is square root of three times bigger than the shortest side.

16)8(2 38

Page 10: Triangles and Lines – Special Right Triangles There are two special right triangles : 30 – 60 – 90 degree right triangle 45 – 45 – 90 degree right triangle

Triangles and Lines – Special Right Triangles

There are two special right triangles :

30 – 60 – 90 degree right triangle

45 – 45 – 90 degree right triangle

30

60

Example # 2 : Find the other two sides if the medium length side =

x

2x

313

In a 30 – 60 – 90 right triangle, the hypotenuse is two times longer than the shortest leg

Using the Pythagorean theorem, we find the third side is square root of three times bigger than the shortest side.

3133x

Page 11: Triangles and Lines – Special Right Triangles There are two special right triangles : 30 – 60 – 90 degree right triangle 45 – 45 – 90 degree right triangle

Triangles and Lines – Special Right Triangles

There are two special right triangles :

30 – 60 – 90 degree right triangle

45 – 45 – 90 degree right triangle

30

60

Example # 2 : Find the other two sides if the medium length side =

x = 13

2x

313

In a 30 – 60 – 90 right triangle, the hypotenuse is two times longer than the shortest leg

Using the Pythagorean theorem, we find the third side is square root of three times bigger than the shortest side.

3133x

Page 12: Triangles and Lines – Special Right Triangles There are two special right triangles : 30 – 60 – 90 degree right triangle 45 – 45 – 90 degree right triangle

Triangles and Lines – Special Right Triangles

There are two special right triangles :

30 – 60 – 90 degree right triangle

45 – 45 – 90 degree right triangle

30

60

Example # 2 : Find the other two sides if the medium length side =

x = 13

2x = 26

313

In a 30 – 60 – 90 right triangle, the hypotenuse is two times longer than the shortest leg

Using the Pythagorean theorem, we find the third side is square root of three times bigger than the shortest side.

3133x

26)13(2

Page 13: Triangles and Lines – Special Right Triangles There are two special right triangles : 30 – 60 – 90 degree right triangle 45 – 45 – 90 degree right triangle

Triangles and Lines – Special Right Triangles

There are two special right triangles :

30 – 60 – 90 degree right triangle

45 – 45 – 90 degree right triangle

45

45

Remember, sides opposite equal angles are congruent. If we let AC and BC = 1 and use Pythagorean theorem…

1

1

A

C B

?

Page 14: Triangles and Lines – Special Right Triangles There are two special right triangles : 30 – 60 – 90 degree right triangle 45 – 45 – 90 degree right triangle

Triangles and Lines – Special Right Triangles

There are two special right triangles :

30 – 60 – 90 degree right triangle

45 – 45 – 90 degree right triangle

45

45

Remember, sides opposite equal angles are congruent. If we let AC and BC = 1 and use Pythagorean theorem…

1

1

A

C B

2

2

112

222

c

c

c

2

Page 15: Triangles and Lines – Special Right Triangles There are two special right triangles : 30 – 60 – 90 degree right triangle 45 – 45 – 90 degree right triangle

Triangles and Lines – Special Right Triangles

There are two special right triangles :

30 – 60 – 90 degree right triangle

45 – 45 – 90 degree right triangle

45

45

The hypotenuse of a 45 – 45 – 90 right triangle is square root two times larger than the equal sides…

x

x

A

C B

2x

Page 16: Triangles and Lines – Special Right Triangles There are two special right triangles : 30 – 60 – 90 degree right triangle 45 – 45 – 90 degree right triangle

Triangles and Lines – Special Right Triangles

There are two special right triangles :

30 – 60 – 90 degree right triangle

45 – 45 – 90 degree right triangle

45

45

The hypotenuse of a 45 – 45 – 90 right triangle is square root two times larger than the equal sides…

6

6

A

C B

2x

Example # 1 : Find the hypotenuse if the congruent sides = 6

Page 17: Triangles and Lines – Special Right Triangles There are two special right triangles : 30 – 60 – 90 degree right triangle 45 – 45 – 90 degree right triangle

Triangles and Lines – Special Right Triangles

There are two special right triangles :

30 – 60 – 90 degree right triangle

45 – 45 – 90 degree right triangle

45

45

The hypotenuse of a 45 – 45 – 90 right triangle is square root two times larger than the equal sides…

6

6

A

C B

26

Example # 1 : Find the hypotenuse if the congruent sides = 6

Page 18: Triangles and Lines – Special Right Triangles There are two special right triangles : 30 – 60 – 90 degree right triangle 45 – 45 – 90 degree right triangle

Triangles and Lines – Special Right Triangles

There are two special right triangles :

30 – 60 – 90 degree right triangle

45 – 45 – 90 degree right triangle

45

45

The hypotenuse of a 45 – 45 – 90 right triangle is square root two times larger than the equal sides…

x

x

A

C B

215

Example # 2 : Find the congruent sides if the hypotenuse = 215

Page 19: Triangles and Lines – Special Right Triangles There are two special right triangles : 30 – 60 – 90 degree right triangle 45 – 45 – 90 degree right triangle

Triangles and Lines – Special Right Triangles

There are two special right triangles :

30 – 60 – 90 degree right triangle

45 – 45 – 90 degree right triangle

45

45

The hypotenuse of a 45 – 45 – 90 right triangle is square root two times larger than the equal sides…

15

15

A

C B

215

Example # 2 : Find the congruent sides if the hypotenuse = 215