\(\text {ABC is an isosceles triangle inscribed in a circle of radius r. If AB = AC and h is the altitude from A to BC, then the triangle has area A is equal to
\(In~ \Delta ABC, AB = BC \text{and altitude} AD = h\\
\text{Let r be the radius of circumscribed circle.}\\
∴PA=PB=PC=r
∴PD=h−r
Now, BD=√BP2−PD2
=√r2−(h−r)2
=√2rh−h2
∴BC=2BD=2√2rh−h2
Thus, are of ΔABC=12×BC×DA