Question

The longest side of a triangle is a cm.

The second side is bcm 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

• P = 2.5a - 1.5b

Explanation:

The sides of the triangle are:

• a cm,
• a - b cm,
• (a - b)/2 cm.

Its perimeter is the sum of the three sides:

• P =
• a + a - b + (a - b)/2 =
• 2a - b + 0.5a - 0.5b =
• 2.5a - 1.5b