Question

Determine the length of AB (round your answer to the nearest whole number)?

Answer 1

AB ≈ 13 cm

Explanation:

∠ CAB = 90° - ∠ CAD = 90° - 45° = 45°

using the cosine ration in right triangle ABC

cos45° =
`(adjacent)/(hypotenuse)` =
`(AC)/(AB)` =
`(9)/(AB)` ( multiply both sides by AB )

AB × cos45° = 9 ( divide both sides by cos 45° )

AB =
`(9)/(cos45)` ≈ 13 cm ( to the nearest whole number )