Algebraic Perimeters

Question

A kite has a perimeter of 3318 millimetres. It's longer sides are ten percent longer than its shorter sides. Find the length in millimetres of one of the shorter sides.

Answer 1

perimeter = x+x+.9x+.9x = 3.8x = 3318

x = longer side = 3318/3.8 = about 873.16 mm

.9x = shorter side = .9(873.16 = about 785.84 mm

10% shorter = 90% of the longer = .9x

10% of 873.16 = 87.316

perimeter = 2x +2(.9x) = 2(873.16) + 2(785.84) =1746.32 + 1571.68 = 3318 mm

873.16 - 87.316 = 785.84 mm= shorter side