Similar Triangles Worksheet

Solve for y.

Ms. Mac used similar triangles to make a design. 

Which statement about the triangles in the design must be true?

• They are the same size and shape.

• They are the same size but different shapes.

• They have corresponding angles that are congruent.

• They have corresponding sides that are congruent.

Tell whether the triangles are similar. Explain.

• Yes because it looks like it

• Yes because 81 + 48 + 51 = 180

• No because 81 + 48 + 51 =/= 180

• Def not

The pair of figures is similar. Find the missing side.

Set up a proportion.
Write an equation.

Solve.

• x = 1

• x = 3

• x = 9

• x = 5

Find missing side.

Set up a proportion.
Write an equation.

(Use x for the missing side length.)

Solve.

• 5

• 7

• 9

• 11

Find side length X.

Redraw the triangles.

Set up a proportion.
Write an equation.

Solve.

• 30

• 25

• 15

• 40

Tell whether the triangles are similar. Explain.

• Yes because it looks like it

• Yes because 36 + 72 + 33 = 180

• No because 36 + 72 + 33 =/= 180

• Def not

Find the value of y.

Set up a proportion.
Write an equation.

Solve.

• 24

• 16

• 6

• 54

What angle corresponds with A? 

• D

• F

• C

• E

Are triangle ABC and triangle DEF similar?

• No

• Yes