Two supplementary angles have measurements of (3x)° and (10x – 15)°. What are the measures of the two angles?

Mathematics · High School · Thu Feb 04 2021

Answered on

Given:

Angle 1 = 3x

Angle 2 = 10x - 15

Find the measurement of the two angles, if the two angles are supplementary.

Solution:

Supplementary angles, are angles that add up to 180 degrees, hence we can equate the two equations into one single solution separated by a plus sign and having a sum of 180.

(3x) + (10x - 15) = 180

Now in order to find the angles we simply need to solve for x.

3x + 10x - 15 = 180

13x - 15 = 180

Transpose -15 to the other side of the equation, hence it must be taken to note that in transposing a number, the sign changes.

13x = 180 + 15

13x = 195

Divide both sides by 13 in order to cancel out 13x, leaving behind x.

13x/13 = 195/13

x  = 15

Angle 1 = (3)(15)
Angle 1 = 45°

Angle 2 = 10 (15) - 15
Angle 2 = 135°

Final answer:

Angle 1 = 45°

Angle 2 = 135°