One side of a triangle is half the longest side. The third side is 9 meters less than the longest side. The perimeter is 61 meters. Find all three sides.

Answer 1

c = the longest side

a = c / 2

b = c - 9

P = a + b + c = 61 m

a + b + c = 61

c / 2 + c - 9 + c = 61 Multiply both sides by 2

c + 2 c - 18 + 2 c = 122

5 c - 18 = 122

5 c = 122 + 18

5 c = 140 Divide both sides by 5

c = 140 / 5

c = 28 m

a = c / 2

a = 28 / 2

a = 14 m

b = c - 9

b = 28 - 9

b = 19 m