Isosceles & Equilateral Triangles

Isosceles & Equilateral Triangles

Mrs. Felig Geometry 2020

Hint: Since this is an equilateral triangle, all the sides are the same!!! That means we can set the expressions for our unknown sides equal to 10.

Fill in the Blanks

From the last slide, what did you get for x and y? (type answers as x,y)

Hint: What do each of the angles of an equilateral triangle have to be?

Fill in the Blanks

From the last slide, what did you get for the angle measure and y? (type answers as angle measure, y)

Multiple Choice

What do the angles in an equilateral triangle measure?

• 30, 60, 90
• 60, 60, 60
• 45, 45, 90
• 35, 55, 90

Multiple Choice

The sides of an equilateral triangle have...

• different measures.

• equal angles

• equal measures.

• 60°.

Multiple Choice

Find x

• 3
• 4
• 2
• 10

Multiple Choice

What is the length of DF?

• 8

• 4

• 25

• 71

Hint: In an isosceles triangle, the two base angles are congruent. If you need to find the vertex angle, just remember what all three angles should add up to!

Fill in the Blanks

From the last slide, what did you get for x and

 $m\angle A$  ? (type answers as x,  $m\angle A$  )

Hint: In an isosceles triangle, exactly two sides are congruent!

Fill in the Blanks

From the last slide, what did you get for x and the segment measure? (type answers as x, segment measure)

Hint: Start by solving for y...remember the two base angles are congruent! Then, you can find x using your knowledge of what the three angles of a triangle should add up to!

Fill in the Blanks

From the last slide, what did you get for x and y? (type answers as x, y)

Multiple Choice

If two sides of a triangle are congruent, then the _________________ opposite those sides are congruent.

• sides
• vertices
• angles
• measures

Multiple Choice

Find x

• 10
• 32
• 116
• 16

Multiple Choice

What is the measure of ∠S?

• 60⁰

• 52⁰

• 45⁰

• 36⁰

Multiple Choice

What is the measure of ∠A?

• 46

• 134

• 90

• 88

Multiple Choice

• A
• B
• C
• D