A constant that multiplies a variable?

A constant that multiplies a variable is no longer a constant. By its very definition, a constant is something that can never be different. The result of variable multiplication is thus a variable, not a constant.

I would say that the above answer is not necessarily true. The common equation for the area of a circle is: area = pi * r2

The fact that you are multiplying the mathematical constant pi by a variable does not change the value of pi.

Agree with the second answer. Jsut to add, a constant that multplies a variable is called a coefficient.