Isosceles Triangles Practice (Proof)

What are the different parts of an isosceles triangle?

• 1 leg, 2 vertex angles, 1 base, and 2 base angle

• 1 leg, 2 vertex angles, 2 bases, and 1 base angle

• 2 legs, 1 vertex angle, 1 base, and 2 base angles

• 2 legs, 1 vertex angle, 2 bases, and 1 base angle

Tags

CCSS.HSG.CO.C.10

All the following properties of an isosceles triangle are true EXCEPT...

• the two legs are congruent

• all three sides of the triangle add up to 180°

• the base angles are congruent

• all three angles of the triangle add up to 180°

The first part of the Isosceles Triangle Theorem Proof is...

• drawing an angle bisector

• stating that two right triangles are formed and congruent

• stating that two legs are congruent

• using the Reflexive Property

The measure of the vertex angle of an isosceles triangle is 113°. What is the measure of a base

angle?

• 113°

• 33.5°

• 67°

• 56.6°

Tags

CCSS.8.G.A.5

The measure of a base angle of an isosceles triangle is 45°. What is the measure of the vertex

angle?

• 135°

• 64.5°

• 90°

• 45°

Tags

CCSS.8.G.A.5

What is the measure of the missing angle?

• 114°

• 106°

• 96°

• 111°

Tags

CCSS.7.G.B.5

What is the measure of the missing angle?

• 60°

• 75°

• 98°

• 55°

Tags

CCSS.8.G.A.5

What is the measure of the missing angle?

• 40°

• 51°

• 32°

• 50°

Tags

CCSS.8.G.A.5

What is the measure of the missing side?

• 11

• 9

• 8

• 7

Use the Isosceles Triangle Theorem to find the value of x.

• -7

• -8

• -12

• 6

Tags

CCSS.HSG.CO.C.9