Question

A momento is made as shown in the figure. Its base PBCR is silver plated from the front side. Find the area which is silver plated, where AP = AR = 7 $cm$ and PB = RC = 3 $cm$. $(Use\pi =\frac{22}{7})$

• A. $8.5c{m}^2$
• B. $9.5c{m}^2$
• C. $10.5c{m}^2$
• D. $11.5c{m}^2$

Answer 1

The correct option is D $11.5c{m}^2$

From the given figure,
Area of right-angled $\Delta ABC=\frac{1}{2}\times 10\times 10$
$=50c{m}^2$
Area of quadrant
$APR$ of the circle of radius $7cm$
$=\frac{1}{4}\times \pi \times (7{)}^2$
$=\frac{1}{4}\times \frac{22}{7}\times 49$
$=38.5c{m}^2$
$\therefore$ Area of base
$PBCR=$ Area of $ABC$- Area of quadrant $APR$
$=50-38.5=11.5c{m}^2$