Area of triangle = 1/2 * base * height

72cm^2 = 1/2 * x*x ( since it is isoceles)

72 * 2 = x^2

144 = x^2

√144 = x

x = 12.

Base =12cm , perpendicular side=12

By pythagorus theorem ,

(H)^2 = (B)^2 + (P)^2

(H ) ^2 = 12^2 + 12^2

(H)^2 = 144+ 144

(H)^2 = 288

H = √288