Answer:
That would be A my good Sir (or ma'am).
Explanation:
A triangle has a total of 180 degrees in it , however we already know one side is 45, so we can add that to the solution, we also know that 2 sides are the exact same, so therefore, we will be multiplying our unknown value ( x = 67.5 btw, not so unknown) by 2, and you will always get 180 degrees, thats how you check your answer, also if you sbutract 45 from 180 and divide the product by 2 you will get the value of x ( which is 67.5).
Thats It Helps It Helps!