Answer:
-8
Step-by-step explanation:
All triangle angles must add up to 180.
If we look at the triangle, it has the angles of 40 degrees, and a right angle (90). If we add those together, we get 130.
So that means the top angle must be 50 degrees. Because 40+50+90=180.
So if the top angle is 50, the the other side must be 130. Again, because that is a 180 degree angle, going straight up.
So if we need to get 130, and the answers are not -4 or 3. Then the answer must be -8. Because 138+(-8)=130. Boom.
Hope this helped in some way. Stay safe, and have a good day!
