The least (or lowest) common denominator of 3, 16 and 8 is 16. That already points us to answer A.
Checking for each fraction:
1/2 * 8/8 = 8/16
3/16 * 1/1 = 3/16
7/8 * 2/2 = 14/16
Yep. Answer A.
To find the measure of the s angle que are going use the cosine law because we know all the sides of the triangule:
s² = r² + t² - 2*r*t * cos(S)
Then solve the equation
s² -r² - t² = -2*r*t * cos(S)
arccos ((s² -r² - t² /-2*r*t)) = S
arccos (((250)² -(850 cm)²-(940 cm)² /(-2* 850 cm*940 cm) = S
14.9 = S
round to the nearest 10th of a degree
15º = S
