If one of the equal angles of an isosceles triangle is 65°, then the angle at the vertex is

In ΔABC, D is a point on side BC such that ∠ADC = 2∠BAD. If ∠A = 80° and ∠C = 38°, then what is the measure of ∠ADB?

In a circle, O is the centre of the circle. Chords AB and CD intersect at P. If ∠AOD=32° and <COB = 26°, then the measure of ∠APD lies between:

If the circumradius of an equilateral triangle be 10 cm, then the measure of its in-radius is

The area of a rhombus is 144 square units. The length of one of its diagonals is twice the length of other diagonal. What is the sum of length of its diagonals?

Triangle PQR is inscribed in a circle such that P, Q and R lies on the circumference . If PQ is the diameter of the circle and ∠PQR = 40 ° , then what is the value ( in degrees ) of ∠QPR ?

'G' is centroid of ΔABC if AG = BC then find ∠BGC.

If the ratio of the heights of two identical triangles is 4: 9, find the ratio of the areas of the two triangles.