Question

Find the length of AC.

a. 10.1
b. 10.0
c. 10.9
d. 8.86
PLEASE HELPPP ASAP ​

Answer 1

Option D

Explanation:

According to law of cosines =

`{a}^(2) = {b}^(2) + {c}^(2) - 2bc. \cos(A)`

where 'a' is the uknown side , 'b' & 'c' are the given sides and angleA is the angle opposite to the uknown side i.e. opposite to 'a'.

Using the Law of cosines , we'll find the length of AC .

`{ac}^(2) = {7}^(2) + {13}^(2) - 2 * 7 * 13 * \cos(50)`

`= > {ac}^(2) = 49 + 169 - 182 * 0.76`

`= > {ac}^(2) = 218 - 138.8 = 79.68`

`= > ac = √(79.68) = 8.92 = 9(appx)`

In option D , if we'll round of 8.86 , then its appx 9. So option D is right