Question

What is the value of n to the nearest whole number? Need answer now 

Law of cosines: a2 = b2 + c2 – 2bccos(A)

Answer choices

18
22
29
41

Answer 1

I think the answer is 22 because pythagoras theorem right? √(20^2 + 9^2)

Answer 2

`n=22\ units`

Explanation:

Applying the law of cosines

`c^(2)=a^(2)+b^(2)-2abcos (C)`

In this problem we have

`c=n\ units`

`a=20\ units`

`b=9\ units`

`C=90\°`

Remember that

`cos(90\°)=0`

substitute

`c^(2)=a^(2)+b^(2)` -----> Pythagoras Theorem, because is a right triangle

Find the value of n

`n^(2)=20^(2)+9^(2)`

`n^(2)=481`

`n=21.93\ units`

Round to the nearest whole number

`n=22\ units`