Question

Which of the following statements is not always true?

विकल्प

• Two circles are similar.

• Two isosceles right triangles are similar.

• Two rectangles are similar.

• Two equilateral triangles are similar.

Answer 1

Two rectangles are similar.

Explanation:

(A) Two circles are similar.

All circles are similar because they have the same shape regardless of radius.

(B) Two isosceles right triangles are similar.

All isosceles right triangles have angles 45°, 45°, 90°, so they are similar.

(C) Two rectangles are similar.

Rectangles have all angles 90°, but their sides can be different in ratio.

For similarity, corresponding sides must be in the same ratio.

So, two rectangles are not always similar.

(D) Two equilateral triangles are similar.

All equilateral triangles have all angles 60°, so they are similar.