Question

HELP!!! Please help me with this math problem.

Answer 1

Answer:

i) $r= \sqrt{\frac{A}{\pi} }$

ii) $r=4.15$ centimeters

Step-by-step explanation:

The area of a circle is given by;

$A=\pi r^2$

We want to solve for r.

Divide both sides by $\pi$.

This implies that;

$\frac{A}{\pi} =r^2$

Take positive square root of both sides;

$\Rightarrow r= \sqrt{\frac{A}{\pi} }$

When we substitute;

$A=54cm^2$

and

$\pi=\frac{22}{7}$

We obtain;

$r=\sqrt{\frac{54}{\frac{22}{7} }}$

$r=\sqrt{54\times \frac{7}{22}}$

$r=\sqrt{17.18}$

$r=4.15$ centimeters

Answer 2

Answer:

Part 1: r = √(A/π)

Part 2: 4.15 cm

Step-by-step explanation:

Part 1

The area of a circle is given by;

Area = π r²

A = πr²

dividing both sides by π

r² = A/π

Find the square root on both sides of the equation

r = √(A/π)

Part 2

where π = 22/7 and

           r is the radius os the circle

Area = 54 cm²

πr² = 54

22/7 × r² = 54

Multiplying both sides of the equation by 7/22

7/22 × 22/7 ×r² = 54 ×7/22

r² = 189/11

    = 17.181818..

r = √17.181818

   = 4.145

Answer to the nearest hundredth = 4.15 cm