Question

Find the length of side y

Answer 1

`\large\boxed{y=76.3359\ cm\approx76.3\ cm}`

Explanation:

Use cosine:

`cosine=(adjacent)/(hypotenuse)`

We have

`adjacent=73\ cm\\hypotenuse=y`

and the angle 17°.

`\cos17^o\approx0.9563`

Substitute:

`(73)/(y)=0.9563` convert the decimal to the fraction

`(73)/(y)=(9563)/(10000)` cross multiply

`9563y=730000` divide both sides by 9563

`y=(730000)/(9563)`

`y\approx76.3359`