Question

Find the diamter of a circle if its area is 706.9mm²​

Answer 1

Answer:

30 mm

Step-by-step explanation:

The formula of an area of a circle:

$A=\pi r^2$

r - radius

We have

$A=706.9\ mm^2$

Substitute:

$\pi r^2=706.9$          divide both sides by π

$r^2=\dfrac{706.9}{\pi}$        use π ≈ 3.14

$r^2\approx\dfrac{706.9}{3.14}\\\\r^2\approx225\to r=\sqrt{225}\\\\r= 15\ mm$

The diameter d = 2r.

Therefore

$d=2(15)=30\ mm$