ABCD is a cyclic quadrilateral such that AC is a diameter of the circle. If ∠BAC = 58° and ∠DAC = 65°, then ∠BCD is equal to :

1. 57°

2. 123°

3. 90°

4. 60°

The angle formed in a minor segment of a circle is :

1. an acute angle

2. an obtuse angle

3. a right angle

4. either an acute or an obtuse angle

An equilateral triangle ABC is inscribed in a circle with centre O. The measure of ∠BOC is :

1. 120°

2. 60°

3. 90°

4. 30°

If two diameters of a circle intersect each other at right angles, then the quadrilateral formed by joining their end points is a :

1. rhombus

2. square

3. rectangle

4. parallelogram