Question

in a circle of diameter 40 cm a rhombus is inscribed with all its vertices on the circle.find the area of rhombus.

Answer 1

if rhombus inscribed with all its vertices on the circle 
it is called cyclic rhombus becomes a square
area of the rhobus = area of the square
=(diagonal)²/2
=(diameter)²/2 [since length of the diagonal = diameter of the circle]
=(40)²/2
=(40*40)/2
=40*20
=800sq cm