Question

AB is a diameter of a circle and C is any point on the circumference of the circle, then

• A. The area of DABC is maximum when it is isosceles.
• B. The area of DABC is minimum when it is isosceles
• C. The perimeter of DABC is maximum when it is isosceles
• D. None

Answer 1

Answer: (A)

The area of DABC is maximum when it is isosceles.

Answer 2

Area of triangle = $\frac { 1 } { 2 }$(base). Height

Area of triangle is maximum if height of the triangle is maximum

Maximum height = r

Hence area of DABC is maximum when it is isosceles.