The perimeter of an equilateral triangle is 36 cm. What is its area in square cm? (Take √3 = 1.73.)

Each side is 36/3 = 12 cm, and the area of an equilateral triangle is (√3/4) $x$ sid$e^2=(1.73/4)\times 144=1.73\times 36=62.28$ sq cm. The trap 124.56 uses √3/2 in place of √3/4; 72 comes from $(1/2)\times 12\times 12$, using a side as though it were the height, though the true height is 6√3 ≈ 10.38 cm; 35.03 divides the perimeter by 4 instead of 3, giving a side of 9 cm.