Let the breadth be B kilometers. Then the length is 1.5B kilometers. Write an equation for the perimeter B + 1.5B + B + 1.5 B = 10 kilometers. Simplify and find B 5B = 10, B = 10/5 = 2. ANSWER. The breadth is 2 kilometers. The length is 1.5*2 = 3 kilometers.