This lesson includes 64 additional questions and 315 additional question variations for subscribers.

# Lesson Worksheet: Angle-Angle Triangle Similarity Mathematics

In this worksheet, we will practice determining whether two triangles are similar using the equality of corresponding angles (Angle-Angle criteria) and using the similarity to find unknown angles.

**Q1: **

Find the length of .

**Q2: **

The figure shows triangle .

Work out the value of .

Work out the value of .

Work out the perimeter of .

**Q3: **

In the given figure, lies on both and . and each have a length of 4, and has a length of 3.

Calculate the length of .

- A
- B5
- C4
- D3
- E

Calculate the length of .

Hence, calculate the length of .

- A
- B1
- C
- D3
- E4

**Q4: **

Determine the length of .

**Q5: **

If , find the length of .

**Q6: **

In the two triangles shown, and . What is ?

**Q7: **

What does the AA criterion for triangles allow us to prove?

- AIf two corresponding angles in two triangles have equal measures, then they must be similar.
- BIf the corresponding sides of two triangles are proportional, then the two triangles are similar.
- CIf, in the two triangles, one pair of corresponding sides are proportional and the included angles are equal, then the two triangles are similar.
- DIf a corresponding side and angle are equal in two triangles, then the two triangles are similar.
- EIf the corresponding sides of two triangles are equal, then the two triangles are congruent.

**Q8: **

Find the length of .

**Q9: **

Triangles and in the given figure are similar. What, if anything, must be true of the lines and ?

- AThey are parallel.
- BThey are perpendicular.

**Q10: **

In the given figure, and are parallel. Using the AA criterion, what can we say about triangles and ?

- AThey are congruent.
- BThey are neither similar nor congruent.
- CThey are isosceles triangles.
- DThey are similar.
- EThey are equilateral triangles.