Question

Fig. shows two concentric circles with diameter $100cmand80cm$. Find the area of the shaded region. (Use $\pi =3.14$)

• A. $2826c{m}^2$
• B. $2816c{m}^2$
• C. $2526c{m}^2$
• D. $2626c{m}^2$

Answer 1

The correct option is A $2826c{m}^2$

Area of shaded portion

$=\pi (r_2^2-r_1^2)$

$=3.14({\left(50\right)}^2-{\left(40\right)}^2)$

$=3.14\times 900$

$=2826$ ${cm}^3$