Triangles
Find the Missing Angle
Vocabulary
Missing Triangle Angles
Find x
100

What type of triangle has three angles that are less than 90º?

Acute Triangle

100

What is the measurement of angle COD?

90º

100

What is the name of an angle that is greater than 90º?

Obtuse Angle

100

What is the measurement of angle C?

65º

100

What is x?

100º

200

What type of triangle is this?

Isosceles Triangle

200

What is the measurement of an angle that is complementary to an angle that is 32º?

58º

200

What is the name of two angles that add up to 180º?

Supplementary Angles

200

What is the measurement of the third angle of an Isosceles triangle with two angles that measure 50º?

80º

200

What is t?

t=18

300

Give two different names for this triangle.

Acute and Equilateral

300

What is the measurement of angle e?

97º

300

What is the name of two angles that add up to 90º?

Complementary

300

What is the measurement of angle C?

72º

300

What is x?

30

400

Can you make a scalene triangle with side lengths of 12, 18, and 29? Explain how you know.

Yes because all sides have different lengths and if you add two sides, they are greater than the third side.

12 + 18 > 29
12 + 29 > 18
18 + 29 > 12

400

What is the measurement of angle n?

52º

400

What is the name of two angles that are next to each other and share a side?

Adjacent angles

400

What is the measurement of angle x?

111º

400

What is x?

12

500

Draw an obtuse isosceles triangle with one angle that measures 120º. Then give three possible side lengths. 

Two other angle measurements are 30º and 30º. Side lengths can vary as long as they meet the triangle inequality theorem and have two sides that are the same.

500

What is the measurement of angle z?

50º

500

What is the theorem that states that the sum of two sides on a triangle must be greater than the third side?

Triangle Inequality Theorem

500

Find the measurement of each angle.

x=34

3x=102

x+10=44

500

What is x?

80º

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