A circle and a rectangle have the same perimeter. The sides of the rectangle are 18 cm and 26 cm. The area of the circle is:

Find the value of ∠OBE=?

If one angle is half of its complementary angle, find that angle.

What is the area (in cm²) of the circumcircle of a triangle whose sides are 6 cm, 8 cm and 10 cm respectively?

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?

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

The exterior angle of a regular polygon is one-third of its interior angle, the number of sides of the polygon is -

Find the area of the largest triangle made in a semicircle of r cm radius?