Find base angles of an isoceles triangle using 2 variables.

Question

The vertex angle of an isoceles triangle is 100 degrees. One other angle is 3x+y and the other angle is 2x-y. Solve for x and y

Answer 1

You have two pieces of information:

The base angles plus the vertex angle must add up to 180

The base angles are equal in measure, so each equals half of the (180 - vertex angle)

Now you have a system of equations to solve (set each expression of a base angle equal to the correct number of degrees)

Hope this helps--Andrew F.