You recently bought a new bookshelf with a base in the shape of an isosceles trapezoid. If the small base is 2 feet, the large base is 3 feet, and the arms are 1.5 feet, what is the perimeter of the base of your new bookshelf?

Find the perimeter of the trapezoid:

The perimeter of the following trapezoid is equal to 23 cm. Solve for . (Figure not drawn to scale.)