over lesson 10–2 a.a b.b c.c d.d 5-minute check 5 a.6.5 ft b.6.6 ft c.6.7 ft d.6.8 ft
TRANSCRIPT
Over Lesson 10–2
A. A
B. B
C. C
D. D
A. 6.5 ft
B. 6.6 ft
C. 6.7 ft
D. 6.8 ft
You solved equations by adding or subtracting.(Lesson 4–3)
• Find the missing angle measure of a triangle.
• Classify triangles by properties and attributes.
• line segment
• triangle
• vertex
• congruent
Part of a line containing two endpoints and all the points between them
A Figure having three sides
The two sides of a triangle (polygon) intersect
Line segments that have the same length, or angles that have the same measure, or figures that have the same size and shape
Find Angle Measures
100 + 33 + x = 180 Substitution
133 + x = 180 Simplify.
133 – 133 + x = 180 – 133 Subtract 133 from each side.
x = 47 Simplify.
Answer: x is 47, so mF = 47°.
Find the value of x in ΔDEF.
Write an equation.
A. A
B. B
C. C
D. D
A. 57
B. 123
C. 139
D. 303
Find the value of x in ΔMNO.
Use Ratios to Find Angle Measures
ALGEBRA The measures of the angles of a triangle are in the ratio 2:3:5. What are the measures of the angles?
Use Ratios to Find Angle Measures
10x = 180 Combine like terms.Divide each side by 10.
Answer: The measures of the angles are 36°, 54°, and 90°.
x = 18 Simplify.
Since x = 18, 2x = 2(18) or 36, 3x = 3(18) or 54, and 5x = 5(18) or 90.
2x + 3x + 5x = 180 Write the equation.
A. A
B. B
C. C
D. D
A. 12°, 60°, 84°
B. 30°, 50°, 70°
C. 36°, 60°, 84°
D. 40°, 60°, 80°
ALGEBRA The measures of the angles of a certain triangle are in the ratio 3:5:7. What are the measures of the angles?
Classify Angles
HUMAN JAWS Humans have jaws that can open to about 45°. What type of angle is formed by the jaws of a human?
Answer: 45° is less than 90°, so it is an acute angle.
A. A
B. B
C. C
D. D
A. acute
B. right
C. obtuse
D. straight
A bird’s beak can open to about 80°. What kind of angle is this?
Classify Triangles
A. Classify the triangle below by its angles and by its sides.
Answer: The triangle is an obtuse scalene triangle.
Angles: The triangle has an obtuse angle.
Sides: The triangle has no congruent sides.
Classify Triangles
B. Classify the triangle by its angles and by its sides.
Answer: The triangle is a right isosceles triangle.
Angles: The triangle has a right angle.
Sides: The triangle has two congruent sides.
A. A
B. B
C. C
D. D
A. right isoceles
B. obtuse isoceles
C. obtuse scalene
D. acute equilateral
A. Classify the triangle by its angles and by its sides.
A. A
B. B
C. C
D. D
A. right scalene
B. obtuse scalene
C. obtuse isoceles
D. acute equilateral
B. Classify the triangle by its angles and by its sides.
