Question

Given the triangle, find the length of X. Give your answer in simpliest radical form.

Answer 1

x = 4
`√(2)`

Explanation:

using the cosine ratio in the lower right triangle and the exact value

cos45° =
`(1)/(√(2) ) }` , then

cos45° =
`(adjacent)/(hypotenuse)` =
`(4)/(x)` =
`(1)/(√(2) )` ( cross- multiply )

x = 4
`√(2)`