please help.

Question

Answer 1

7).

Step 1 :

In ,  .

Law of cosines for : .

Substitute the values in above equation.

Step 2 :

Law of cosines for :  .

Substitute corresponding values.

.

Step 3 :

Sum of the angles of a traingle is .

Solution :

, and .

Answer 2

8).

Step 1 :

In , and in.

Sum of the angles of a triangle is .

Step 2 :

Law of sines :.

Consider .

Substitute , and in above expression.

step 3 :

Consider .

Substitute corresponding values in above equation.

Solution :

, in, and in.