Answer: 37
Explanation:
If you add in all numbers inside the triangle, it should be equal to 180 degrees meaning x + 98 + 45 = 180.
To solve the unknown, we must first add in the numbers:
x + 143 = 180
To get the variable by itself, we must subtract 143 to both sides which gives us 37 degrees.
Now that we know that x is equal to 37, we should make sure it is the right answer, to do that, we need to replace x with 37:
37 + 98 + 45 = 180
By adding in all the numbers, we should get 180.