Question

A railroad crossing sign is a circle with a diameter of 30 in. The manufacturer makes 6 railroad crossing signs from the sheet of aluminum by arranging the signs as shown. About ____ in2 of aluminum is left over after the signs have been made. (Enter only the number rounded to the nearest square inch.)

Answer 1

gg easy

find the area of 1 circle then times 6
find area of whole sheet
minus area of circles from area of whole sheet

area of circle=pir^2
d=30
d/2=r=30/2=15
area=pi15^2
area=pi225
6 circles so times 6
225pi times 6=1350pi
aprox pi=3.141592 to evaluate
4241.1492 in^2

area of sign=90 by 60=5400


area not used=sheet-signs
areanotused=5400-42441.1492=1158.8508
round
1159

answer is 1159 in^2 unused
aprox pi=3.14