Question

Change the subject of formula for $h$.
$A=2\pi r(r+h)$

• A. $\frac{A-3\pi r^2}{7\pi r^2}$
• B. $\frac{A+2\pi r^2}{6\pi r}$
• C. $\frac{A+2\pi r^2}{3\pi r}$
• D. $\frac{A-2\pi r^2}{2\pi r}$

Answer 1

The correct option is D $\frac{A-2\pi r^2}{2\pi r}$

Given, $A=2\pi r(r+h)$

We have to make subject as $h$

$\therefore A=2\pi r^2+2\pi rh$

$\therefore A-2\pi r^2=2\pi rh$

$\therefore h=\frac{A-2\pi r^2}{2\pi r}$

This is the required expression.