You can use the formula A = C/4 to find the area of a circle given the circumstance. Describe another way to find the area of a circle when given the circumstance. Help please!<…

Question

asked Jan 5, 2022 139k views

1 Answer

Maksim Kondratyuk · Answer 1 · 2022-01-12T09:43:46+0000

Answer:

A = (Cr)/(2)

Explanation:

Given

A = (C)/(4)

Required

Describe another way to get area from circumference

Circumference C is calculated using:

$C = 2\pi r$

Area, A is calculated using:

$A = \pi r^2$

Using:
$C = 2\pi r$

Divide both sides by 2

$(C)/(2) = (2\pi r)/(2)$

$(C)/(2) = \pi r$

Multiply both sides by r

$r*(C)/(2) = \pi r*r$

$r*(C)/(2) = \pi r^2$

$(Cr)/(2) = \pi r^2$

The expression on the right-hand side is the area.

So, substitute
$\pi r^2$ for A

(Cr)/(2) = A

Reorder

A = (Cr)/(2)