Question

In figure, you see the frame of a lampshade. It is to be covered with a decorative cloth. The frame has a base diameter of $20$ cm and height of $30$ cm. A margin of $2.5$ cm is to be given for folding it over the top an bottom of the frame. Find area of cloth required for covering the lampshade.

• A. $2200{cm}^2$
• B. $4200{cm}^2$
• C. $3200{cm}^2$
• D. $1200{cm}^2$

Answer 1

Answer: (A)

Given,
$2r=20cm$
$\therefore r=10cm$
$H=30cm$
Margin $=2.5cm$

$\therefore$ cloth required $=2\pi r(h+2.5+2.5)$

$=2\pi r(30+2.5+2.5)$

$=2\times \frac{22}{7}\times 10\times 35$

$=2200c{m}^2$