How much will it cost to paint a circular sign with a radius of 4 feet if the painter charges $1.50 per square foot?

2 Answers
Nov 14, 2015

$75.40

Explanation:

First, we must find the area. The formula for the area of a circle is #A=pir^2#, and we know from the question that #r=4#.

Therefore, #A=pi(4^2)=color(blue)(16pi)# square feet.

Since the painter charges #$1.50# per square foot, he would charge a total of #16pi*1.50=color(red)($75.40)#.

Nov 14, 2015

$75.39

Explanation:

The area of a circle is given by the formula #pir^2#. Plugging the radius into the equation, we get:
#pi times 4^2=16pi, or 50.26ft^2#

If the sign costs $1.50 per square foot, then the cost for the sign is:
#50.26 times $1.50 =$75.39#