Question

What is the length of leg s of the triangle below?
45
4-12
90°
45

Answer 1

A

Explanation:

Using the cosine ratio in the right triangle and the exact value

cos45° =
`(1)/(√(2) )` , then

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

s ×
`√(2)` = 4
`√(2)` ( divide both sides by
`√(2)` )

s = 4 → A