Three points A, B and C lie on circle with centre of O in such a way that AOCB is a parallelogeram.Find the value of `angle AOC`.

OABC is a rhombus whose three vertices A,B and C lie on a cricle with centre O. If the radius of the circle is 10 cm. Find the ara of the rhombus

OABC is a rhombus whose three vertices A,B and C lie on a cricle with centre O. If the radius of the circle is 10 cm. Find the ara of the rhombus

If the points A(4, 3) and B(x, 5) lie on a circle with the centre O(2, 3), find the value of x.

Points A(-1, y) and B(5, 7) lie on a circle with centre O(2, -3y) . Find the values of y.

If the points A(4, 3) and B(x, 5) lie on a circle with the centre O(2, 3), find the value of x.

If the points A(8, 6) and B(x, 10) lie on the circle whose centre is (4, 6) then find the value of x .

In the adjoining figure, O is the centre of the circle. Find the value of angle BEC .

In the adjoining figure, O is the centre of the circle. Find the value of angle BEC .

In Fig. 12.36 A, B and C are three points on a circle with centre O such that BOC=30^@ and AOB = 60^@ . If D is a point on the circle other than the arc ABC, find ADC.