Two sides of a triangle have the same length. The third side measures 7m less than twice the common length. The perimeter of the triangle is 17m. What are the lengths of the three sides? What is the length of the two sides that have the same length?
if the full perimeter is 17 and one side is just 7 then you can subtract 7 from 17 and get ten so then you can divide ten by two and get 5 for both sides.