Question

Please help me with part c! Thank you!

Answer 1

Answer:

15√3/14.

Step-by-step explanation:

C.  The longest side x + 2 = 7 is opposite the largest angle 120 degrees. The other 2 sides are of length 3 and 5.

Using the Sine Law:

sin 120 = √3/ 2 = sin A'

7 / sin 120 = 5/ sin B

sin B =  5 sin 120 / 7 =  5√3/14.

7 / sin 120 = 3 / sin C

sin C =  3 sin 120 / 7 =  3√3 / 14

sin A + sin B + sin C =   √3/ 2  +   5√3/14 +  3√3 / 14

=  7√3/ 14  +   5√3/14 +  3√3 / 14

= 15√3/14.