Question

A triangle has sides of 4 in., 9 in., and 15 in. If the dimensions are doubled, how has the perimeter of the triangle changed?

Answer 1

If the sides of a triangle are a, b, and c. We can say that a+b+c=P, the perimeter. So if you double the sides, that's 2a+2b+2c, or 2(a+b+c). What you do to one side of an equation, you have to do to the other, so 2(a+b+c)=2P. When you double the dimensions, you double the perimeter.

Answer 2

Yeah the perimeter is 28in's longer.