Question

A triangular sail has two sides the same length. The third side is 9ft shorter than either of the equal sides. The perimeter of the sail is 63 ft. How long is the shortest side?

Answer 1

$a-length\ one\ of\ the\ same\ sides\\\\a-9-length\ of\ third\ side\\\\a+a+a-9=63\ \ \ \ \ \ |add\ 9\\a+a+a=63+9\\3a=72\ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ |divide\ by\ 3\\a=24\\\\a-9=24-9=15\\\\The\ shortest\ side\ is\ 15.$