It's 180-50-50=180-100=80°
Option C:
We can find the value of PR using law of cosines.
Solution:
Given data:
∠Q = 18°, r = 9.5, p = 6.0
To find which length could be find in the triangle:
Law of cosines:

Substitute a = q, b = r, c = p and A = Q

If we substitute the values given, we can find q.
q = PR

Hence we can find the value of PR using law of cosines.
Option C is the correct answer.
Answer:
Step-by-step explanation:
alternate interior angles
Make an equation - example, two sides are 2x+60-4x+5=180
equal them to 180 because every triangle is equal to 180
when you find x, multiple two times x plus 60,
s x plus 5
thats the only thing i know about it