### Home > PC > Chapter 4 > Lesson 4.2.1 > Problem4-76

4-76.

A circle of radius $10$ cm cut out of cardboard weighs $120$ g.

1. How much would a $60°$ sector weigh?

What part of the entire cardboard would $60°$ represent?

2. How much would a circle of radius $15$ cm cut out of the same cardboard weigh?

What is the area of a circle?

Set up information involving area and weight.

Set up a proportion and solve for the new weight.

Acircle $= πr^2$
Aoriginal $= 100π$
Weightoriginal $= 120$
Anew $= 15^²π = 225π$
Weightnew $=$ ???