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

1. 60°

2. 30°

3. 75°

4. 45°

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

1. rectangle

2. square

3. parallelogram

4. rhombus

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, then the quadrilateral is :

1. rectangle

2. rhombus

3. not a parallelogram

4. parallelogram