Answer:
D, 60 degrees.
Step-by-step explanation:
They have given you expressions instead of each of the angles. All of the angles inside ANY triangle will always add up to 180 degrees (idk why, it's just a rule of trig).
So first we're just going to find the value of x, since all the expressions are in terms of x. this is how we do it:
1) add up all the expressions and equate it to 180 degrees, because we know that all the angles add up to 180 degrees. this gives us:
2x + 4x + 3x + 45 = 180
2) Keep solving, by adding all the x
9x + 45 = 180
3) Keep solving by moving 45 to the other side
9x = 180 - 45
9x = 135
4) Divide both sides by 9, for x
x = 15
Now that we've found the value of x, we can find C. The diagram tells us that C = 4x.
We know that x is 15 degrees, so C = 4 x 15, which equals 60 degrees.
Hope that helped : )
