all the vertices of a rhombus lie on a circle. find the area of the rhombus if the area of the circle is 1256cm2
Given: All the vertices of a rhombus lie on the circle
Let ABCD be the rhuombus.
In a rhombus opposite angles are equal
⇒ ∠A = ∠C ...... (1)
but in a cyclic quadrilateral opposite angles are supplementary
⇒ ∠A + ∠C = 180° ...... (2)
from (1) and (2) we get
Hence ABCD is a square.
and diagonal AC is the diameter (∵ converse of angle in a semicircle is right angle)
Now area of circle = 1256 cm2
⇒ π radius2 = 1256 cm2
Now in right ∆ ABC
AB2 + BC2 = AC2 = (Diameter)2
⇒ 2(side)2 = (2 radius)2
⇒ side2 = 2 radius2
Hence area of ABCD = side2 = 2 radius2