The measures of two angles of a triangle are x and 4x. Which of these expressions represents the measure of the third angle?

A.) 180 + x + 4x

B.) 180 - x - 4x

C.) 180 - x + 4x

D.) 180 + x - 4x

A.) 180 + x + 4x

B.) 180 - x - 4x

C.) 180 - x + 4x

D.) 180 + x - 4x

**Angles of a triangle add up to 180°.**

**The sum of the two given angles is x + 4x.**

Therefore, the missing angle would be:

180 - (x + 4x) {180° minus the sum of the given angles}

= 180 - x - 4x {distributed negative sign through parentheses}

**B.) 180 - x - 4x**

**Ask Algebra House**