Question

What is the length of the hypotenuse in ∆DEF? Round to the nearest tenth.

Answer 1

DE ≈ 5.3

Explanation:

the hypotenuse ( side opposite the right angle ) is DE

using the cosine ratio in the right triangle

cos41° =
`(adjacent)/(hypotenuse)` =
`(DF)/(DE)` =
`(4)/(DE)` ( multiply both sides by DE )

DE × cos41° = 4 ( divide both sides by cos41° )

DE =
`(4)/(cos41)` ≈ 5.3 ( to the nearest tenth )