angles in a_triangle
TRANSCRIPT
Reading AnglesReading Angles
When reading angles the middle letter is When reading angles the middle letter is always the vertex.always the vertex.
A B
C
GH D
F
E
I
Angles in a TriangleAngles in a Triangle
L.I. We are learning that interior L.I. We are learning that interior angles of a triangle will always angles of a triangle will always
add to 180 add to 180 °°
DefinitionDefinitionAngle Angle – two rays that meet at – two rays that meet at
a common end point.a common end point.
DefinitionDefinitionDegree Degree – a unit of – a unit of
measurement of an angle or measurement of an angle or arc, represented by the arc, represented by the symbol º.symbol º.
30º
DefinitionDefinition
Complementary Angles are angles Complementary Angles are angles that when added together make a that when added together make a right angle, 90.. right angle, 90..
A + B = 90.A
B
DefinitionDefinition
Supplementary Angles are angles Supplementary Angles are angles that when added together are equal that when added together are equal to 180˚.to 180˚.
A + B = 180.A
B
DefinitionDefinitionTriangleTriangle – a polygon with 3 – a polygon with 3
angles and 3 straight sides.angles and 3 straight sides.
Property of trianglesProperty of trianglesThe sum of all the angles The sum of all the angles
equals 180º degreesequals 180º degrees..
90º 30º
60º
Property of trianglesProperty of trianglesThe sum of all the angles The sum of all the angles
equals 180º degreesequals 180º degrees..
90º 30º
60º
60º90º30º+180º
Property of trianglesProperty of trianglesThe sum of all the angles The sum of all the angles
equals 180º degreesequals 180º degrees..
90º 50º
40º
40º90º50º+180º
Property of trianglesProperty of trianglesThe sum of all the angles The sum of all the angles
equals 180º degreesequals 180º degrees..60º60º60º+180º60º 60º
60º
What is the missing What is the missing angle?angle?
70º70º?+
180º70º 70º
?
What is the missing What is the missing angle?angle?
90º30º?+
180º30º 90º
?
What is the missing What is the missing angle?angle?
60º60º?+
180º60º 60º?
What is the missing What is the missing angle?angle?
30º78º?+
180º78º 30º
?
What is the missing What is the missing angle?angle?
40º40º?+
180º40º 40º
?