Question

The semicircle temperature dial on a thermostat has a radius of $2cm$. What is the dial's area?

• A. $6.20c{m}^2$
• B. $3.28c{m}^2$
• C. $4.28c{m}^2$
• D. $6.28c{m}^2$

Answer 1

Answer: (D)

$6.28c{m}^2$

Area of a semicircle $=\frac{1}{2}\pi r^2$
$=\frac{1}{2}\pi (2{)}^2$
$=2\pi$

$=2\times 3.14$
$=6.28$ $c{m}^2$