Sophia H. answered 10/24/19
Math, Science, and Test Prep Tutor
The definition of supplementary angles is that the two angles add up to 180. Let's call the angles angle x and angle y, so that x + y = 180 degrees.
We also know that the difference between these two angles is 10 degrees. Therefore we can say that x - y = 10. Now we have a system of equations.
To solve the system of equations, let's first solve for x in the second equation (you can solve for y as well, whichever makes it easier for you). This gives us the equation: x = 10 + y.
Now that we have that, we can plug in "10+y" for the x in the first equation to get:
(10+y) + y = 180.
Now we just have to solve for y:
(10+y) + y = 180 --> 10 + 2y = 180 --> 2y = 180-10 --> 2y = 170 --> y = 170/2 --> y = 85
Now that we have solved for y, we can plug in the value of 85 for y into the second equation (x-y = 10) to get (x-85 = 10) We can then solve for x to get x = 95.
Now that we have solved for the two angles:
x = 95 and y = 85, we can tell that 85 is the acute angle because it is the angle that is less than 90 degrees.