A circular piece of glass has a radius of 0.8 meters. The glass sells for $4.60 per square meter. What is the total cost of the circular piece of glass?

A.
$2.01

B.
$9.24

C.
$23.11

D.
$36.98

Question

A circular piece of glass has a radius of 0.8 meters. The glass sells for $4.60 per square meter. What is the total cost of the circular piece of glass?	
 
 A.
$2.01
 
 B.
$9.24
 
 C.
$23.11
 
 D.
$36.98

anonymous · Answer

@TheSmartOne

darthvader2900 · Answer

area of circular piece of glass = 3.14 x 0.8 x 0.8 = 2.0096 square meter

cost = 2.0096 x $4.60 = $9.24

thesmartone · Answer

First, we have to find the area of the circle, and then we multiply it by 4.6 to find how much it will cost.

So if the radius is .8, what is the area?

anonymous · Answer

0.4

thesmartone · Answer

Remember

$\sf area= \pi\times r^2$

darthvader2900 · Answer

area of circular piece of glass = 3.14 x 0.8 x 0.8 = 2.0096 square meter

cost = 2.0096 x $4.60 = $9.24

thesmartone · Answer

They already gave us the radius. Last time they gave us the diameter, so we had to calculate the radius. But this time there is no need to divide by 2 :P

anonymous · Answer

2.0096

thesmartone · Answer

And now multiply it by 4.6 to get how much it would cost :)