How to find the radius and diameter of a circle?

Question

I'm working on my math homework, but problem is, I had to leave in the middle of my math class, so I really don't know what I'm doing! It says "Find the diameter and the radius. Use 3.14 for pi. Round to the nearest 10th."... The area is 75cm2. It's kinda confusing. Can you PLEASE help me?! The assignment is due tomorrow!

Answer 1

OK to find area of circle, square the radius and multiply by pi (3.14)

you have the area and 3.14, so turn the equation around,



R squared =75 / 3.14 = 23.88

R = square root of 23.88 = 4.88

R =4.88 cm. Rounding would be 4.9 cm.

The diameter is twice the radius, so 4.9 *2 = 9.8

Diameter is therefore 9.8 cm.

Hope this helps

Answer 2

Area = Pi x the radius squared



and the diameter is just double the radius



so to work out the radius.....divide the area by pi and then square root the whole thing so the radius = square root of (75 / 3.14)



and then the diameter is = 2 x the answer you got above for the radius



Hope that helps x x x

Answer 3

well the formula for a circle is pi times radius squared.

75/pi=23.88535032

to find the radius you have to find the square root of that #.

Square root of 23.853... is 4.887264094.

This means that 4.887264094 is the radius. To find the diameter you multiply the radius by 2 because the radius is the distance from the edge of the circle to the center point. so to find the diameter multiply it by 2. So the diameter is 9.774528187. But you have to round to the nearest 10th.

Radius=4.9

Diameter=9.8

Answer 4

diameter is 2 times the radius so if the the radius (half of the diameter) is 4 then the diameter would be 8. get it???

Answer 5

find square root of 75 then divide answer to get radius then double radius to get diameter

Answer 6

well.

Area = pi x radius squared.

75 = pi x radius squared.

divide by 3.14

23.8 = radius squared.

r = 4.8



the diameters just double the radius.

Answer 7

here is the formula

Radius

piR 2

3.14*the radius squared

Diameter

piD

3.14*the diameter

Answer 8

a diameter is a line that goes directly through the middle of a circle (-)kind of like that and a radius goes from one point of the circle to the ecact middl ( -) kind of like that thats all i know and that question is confusing! i hope i helped!

Answer 9

The formula for are is:



area = pi x r2 (Radius Squared)



So, reverse the equation



Area divided by pi = r2



so 75 divided by 3.14 = r2



square root your r2, and you will get you radius.



Good luck, hope this helps!

Answer 10

radius:

Diameter: d=2r

A=pi r ^2

so, to get r by itself, we put it fo rthe square root o pi, the square root



okay forget it. i honestly have no idea.

https://answersrip.com/question/index?qid=20090223140424AA37oHA&r=w

Answer 11

well, area = pi*r(squared)



so 75=3.14*r(squared)



75/3.14=r(squared)



(square root)23.89=r



2r=d



d=47.78

Answer 12

did u try to measure?