Theory
Exercises
1. 
Find the ratio of the corresponding sides
Difficulty: easy 
2

2. 
Find the area of the similar triangle
Difficulty: easy 
3

3. 
Find the ratio of the areas
Difficulty: easy 
2

4. 
Find the value of the unknown
Difficulty: easy 
3

5. 
Find the unknown part of the triangle
Difficulty: medium 
4

6. 
Determine the perimeter of the similar triangles
Difficulty: medium 
4

7. 
Find the required portion of the triangle
Difficulty: medium 
4

8. 
Find the similarity criterion
Difficulty: medium 
4

9. 
Observe the picture and answer the questions
Difficulty: medium 
4

10. 
Determine the length of DE
Difficulty: medium 
4

11. 
Determine the altitude of the triangle
Difficulty: hard 
4

12. 
Find the length of the shadow
Difficulty: hard 
5

13. 
Determine the lengths of the remaining sides of the triangle
Difficulty: hard 
5

14. 
Find the height of the building
Difficulty: hard 
5

15. 
Determine the height of the man
Difficulty: hard 
5

Tests
1. 
Training test I
Difficulty: easy 
7

2. 
Training test II
Difficulty: medium 
11

3. 
Training test III
Difficulty: hard 
12
