Question

The longest side of a triangle is a cm. The second side is b cm shorter than the first side. The third side is half as long as the second side.

Write an expression, in its simplest form, for the perimeter of the triangle.

Answer 1

2.5a - 1.5 b or

5/2a - 3/2b

Explanation:

a + (a - b) + 0.5(a - b) =

a + a - b + 0.5a - 0.5b =

2a - b + 0.5a - 0.5b =

2a - 1.5 b + 0.5a =

2.5a - 1.5 b