Question

What is the length of leg s of the triangle below?
45
90⁰
1012
S
45°

Answer 1

s = 10

Explanation:

using the cosine ratio with 45° on lower right of right triangle and the exact value

cos45° =
`(1)/(√(2) )` , then

cos45° =
`(adjacent)/(hypotenuse)` =
`(s)/(10√(2) )` =
`(1)/(√(2) )` ( cross- multiply )

s ×
`√(2)` = 10
`√(2)` ( divide both sides by
`√(2)` )

s = 10