The triangle shown at the right is isosceles. That is, it has two sides of an equal length. The third side is 30 m shorter than twice the length of each congruent side. The perimeter is 570 m. Find the length of each side.
We know that perimeter of the triangle its a+b+c=570 Moreover we know that: a=b b=b c=2b-30 Finally we can substitute into our formula b+b+2b-30=570 4b-30=570 /+30 4b=600 /:4 b=150 - its a and b side c=2*b-30 c=300-30 c=270 - its c side
