BEC is an equilateral triangle inside the square ABCD. The value of angle ECD is :

1. 60°

2. 30°

3. 75°

4. 45°

E is the mid-point of side AB and F is the mid point of side DC of parallelogram ABCD. Prove that AEFD is a parallelogram.

If the opposite angles of a quadrilateral are equal, the quadrilateral is :

1. rectangle

2. parallelogram

3. square

4. rhombus

If three angles of a quadrilateral are equal to 90° each, then the quadrilateral is :

1. rectangle

2. square

3. parallelogram

4. rhombus