Question

Which of the following are correct?

• A. All equilateral triangles are always similar.
• B. Similar triangles are always congruent.
• C. Congruent triangles are always similar.
• D. All circles are similar.

Answer 1

Answer: (A), (C), (D)

The correct options are
A

All equilateral triangles are always similar.

C

Congruent triangles are always similar.

D

All circles are similar.

A. Equilateral triangle are those triangles whose all 3 angles are equal to ${60}^{\circ }$
Similar triangles are those triangles which are of same shape.
Since, every equilateral triangles are of same shape, so they are always similar.

B. Similar triangles may have different size.
So, they are not always congruent.

C. Congruent triangles are those triangles whose corresponding sides and angles are equal.
Since, corresponding angles are equal, they are always similar.

D. Shape of all the circles are same so they are similar.