Question

A circular bicycle reflector has a diameter of 5 cm.



What is the approximate area of the reflector? Use 3.14 to approximate pi and round your answer to the nearest hundredth.

Answer 1

@iGreen

Answer 2

@iGreen

Answer 3

@Chiko_1278

Answer 4

ok multiply 3.14 *5 and thats it

Answer 5

Welcome to OpenStudy! Do you know how to find the area of a circle?

Answer 6

Actually, that isn't the correct formula @Chiko_1278

Answer 7

ohhh the area i thought the circumference my bad........

Answer 8

so what is it

Answer 9

haha it's fine :) we all make mistakes

Answer 10

The formula for area of a circle is \(3.14*r^2\). Do you know what the relationship between the diameter and radius is?

Answer 11

well isnt it first the area of a circle and then try to find the circumference?????

Answer 12

Why do we need the circumference?

Answer 13

so what do i multiply

Answer 14

nvm.....just asking.......

Answer 15

They just want the area of the circle

Answer 16

78.5???

Answer 17

@iGreen

Answer 18

is it right

Answer 19

How did you get that?

Answer 20

Okay, I know how you got that. You did \(3.14*d^2\), we need \(3.14*r^2\)

Answer 21

i did 3.14 * 25

Answer 22

Yes, you used the diameter, not the radius. What is the relationship between the diameter and the radius?

Answer 23

howdo i do that

Answer 24

idk

Answer 25

Diameter = 2*radius
Radius = diameter/2

Answer 26

so can u work it out 4 me

Answer 27

I think you can do it :)

Answer 28

2.5

Answer 29

@shamim

Answer 30

help

Answer 31

Yep, that is the radius, now just substitute that into the formula :)

Answer 32

@amorfide

Answer 33

7.85

Answer 34

right???

Answer 35

@sleepyjess

Answer 36

That is just 2.5*3.14

Answer 37

we need \(2.5^2 *3.14\)

Answer 38

19.625

Answer 39

@sleepyjess

Answer 40

Yep :)

Answer 41

yes or no

Answer 42

Yes