Question

if circumference of the circle is 88cm ,find the area of triangle ACB if height is equal to radius CD and base is equal to its diameter AB (use $\pi$ = $\frac{22}{7}$ )

• A. 196$c{m}^2$
• B. 98$c{m}^2$
• C. 49$c{m}^2$
• D. 14$c{m}^2$

Answer 1

The correct option is A 196$c{m}^2$

circumference of triangle
= $\pi$ $\times$diameter
= diameter = $\frac{88}{\pi }$ = $\frac{88\times 7}{22}$
AB = 4$\times$7 = 28cm
radius = CD = $\frac{diameter}{2}$ = $\frac{28}{2}$ = 14cm
height is equal to radius of the circle and base is equal to its diameter
area of triangle ACB = $\frac{1}{2}$$\times$base$\times$height
= $\frac{1}{2}$ $\times$diameter$\times$radius
= $\frac{1}{2}$ $\times$AB$\times$CD
= $\frac{1}{2}$ $\times$28$\times$14 = 14$\times$14
= 196$c{m}^2$