Question

Type the correct answer in the box. Use numerals instead of words. What is DC to the nearest tenth?

Answer 1

DC ≈ 32.3

Explanation:

using Pythagoras' identity in the right triangles

the square on the hypotenuse is equal to the sum of the squares on the other 2 sides.

Δ ABC

BC² + AB² = AC²

BC² + 15² = 22²

BC² + 225 = 484 ( subtract 225 from both sides )

BC² = 259

Δ BCD

DC² = DB² + BC² = 28² + 259 = 784 + 259 = 1043 ( take square root of both sides )

DC =
`√(1043)` ≈ 32.3 ( to the nearest tenth )