Hi there.
A triangle's interior angles must always add up to 180 degrees. Since we already have one measurement, 56, we can set up an equation to solve for the missing angles.
(2x + 4) + 56 + x= 180; solve for x.
Subtract 56 from both sides.
(2x + 4) + x = 124;
Combine like-terms (x).
3x + 4 = 124;
Subtract 4 from both sides.
3x = 120
Divide both sides by 3 to solve for x.
x = 40.
Now, we need to substitute x with 40 in each of our angles to determine their measurements.
2x + 4; x = 40.
2(40) + 4 = 80 + 4 = 84;
One measurement is 84 degrees.
x = 40 is another measurement on its own.
Our measurements are:
56, 84, and 40.
Your corresponding answer choice is H.) 56, 84, 40.
I hope this helps!