Answer:
8.) <u> C = 129.341°</u>
9.) <u> </u><u>C = 90°</u>
10.) <u> </u><u>C = 90°</u>
Step-by-step explanation:
<u>For part 8.</u>
given A=50°, a=15, b=12
In any triangle, the ratio of side length of to the sine of its opposite angle
is the same for all three sides:

Now put the value of A=50°, a=15, b=12 in above formula

Since, the value of Sin50°=0.766



simplify the above,


take inv sin both the sides,

since some of angles of triangle is 180
so,
A + B + C = 180°
50 + 0.659 + C = 180°
50.659 + C = 180°
subtract 50.659 from both the sides,
C = 180°-50.659
<u> C = 129.341°</u>
<u>For part 9</u>
given A=50°, a=10, b=15
Since, 
Now put the value of A=50°, a=10, b=15 in above formula

Since, the value of Sin50°=0.766


simplify the above,


take inv sin both the sides,

since some of angles of triangle is 180
so,
A + B + C = 180°
50° + 40° + C = 180°
90° + C = 180°
subtract 90 from both the sides,
C = 180°-90°
<u> </u><u>C = 90°</u>
<u>For Part 10</u>
given A=47°, a=1.5, b=2
Since, 
Now put the value of A=47°, a=1.5, b=2 in above formula

Since, the value of Sin47°=0.123


simplify the above,


take inv sin both the sides,

since some of angles of triangle is 180
so,
A + B + C = 180°
47° + 43° + C = 180°
90° + C = 180°
subtract 90 from both the sides,
C = 180°-90°
<u> </u><u>C = 90°</u>