Question
Two circular pieces of equal radii and maximum area, touching each other are cut out from a rectangular card board of dimensions $14\ cm × 7\ cm.$ Find the area of the remaining card board.$\Big(\text{Use }\pi=\frac{22}{7}\Big).$
✓
Answer
Length of rectangle $= 14\ cm$
and breadth $= 7\ cm$
$\therefore$ Total area $= l × b$
$= 14 × 7 = 98cm^2$
Radiud of each circle $= \frac{7}{2} \text{cm}$
$\therefore$ Area of two circle $=2\pi\text{r}^2$
$=2\times\frac{22}{7}\times\frac{7}{2}\times\frac{7}{2}=77\text{cm}^2$
Area of the remaining portion
$= 98 - 77 = 21cm^2$
and breadth $= 7\ cm$
$\therefore$ Total area $= l × b$
$= 14 × 7 = 98cm^2$
Radiud of each circle $= \frac{7}{2} \text{cm}$
$\therefore$ Area of two circle $=2\pi\text{r}^2$
$=2\times\frac{22}{7}\times\frac{7}{2}\times\frac{7}{2}=77\text{cm}^2$
Area of the remaining portion
$= 98 - 77 = 21cm^2$
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