In ΔABC, AB = AC and ∠B = 40 °, find the value of ∠A.

ABCD is square and CDE is an equilateral triangle outside the square . What is the value ( in degrees ) of ∠BEC ? 

In a polygon, the sum of the interior angles is double the sum of the exterior angles. What is the number of sides of the polygon?

The length of a chord which is at a distance of 12 cm from the center of a circle of radius 13 cm is 

A secant PAB is drawn from an external point P to the circle with centre O, intersecting it at A and B. If OP = 17 cm, PA = 12 cm and PB = 22.5 cm, then the radius of the circle is:

The Median of an isosceles triangle ΔABC is AD and ∠A = 110 °, AB = AC, find the value of ∠ADB.

If the circumradius of an equilateral triangle ABC is 8 cm, then what is the height of the triangle?

The area of a circle is proportional to the square of its radius. A small circle of radius 3 cm is drawn within a larger circle of radius 5 cm. Find the ratio of the difference between the area of the larger circle and that of the smaller circle to the area of the larger circle.