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.
