Comments on: Help with formulas for circles! Diameter, radius, area and circumference! Please help answer the formulas!?

By: Erin <33

Erin <33 — Fri, 18 Dec 2009 00:38:59 +0000

The radius is half the diameter so you just divide the diameter by two. Then you do Pi X The radius (1/2 diamter) Squared. Circumference = D X Pi or Double Radius X Pi
References :

By: 2008!!

2008!! — Fri, 18 Dec 2009 00:10:59 +0000

area w/ only diamter:
just use pi*radius^2
divide the diamter by two and use the formula

circumference w/ only radius or diameter:
use 2*pi*radius
if u are given the diameter, divide it by two and solve
References :

By: William B

William B — Fri, 18 Dec 2009 00:03:59 +0000

2 times radius = diameter d=2r, r=d/2
If you have the diameter divide it by 2, to get r, the radius.
Area = pi r^2
Circumference = pi x diameter
References :