the perimeter of an isosceles triangle is 28cm with sides 4y = 6y-2x+1 and base x+2y all in cm .find x and y and hence state the lengths of the sides of the triangle. solution. 4y = 6y-2x+1. ; -2y+2x=1.also altitude = |4y|^2=x^2+ |x+2y|^2 =