Hands-on math!

Supplementary angles

Two angles are said to be supplementary if their sum is 180o. This makes them add up to make a straight line. If you take a ruler and bring one end down on a table top, the two angles that the table top makes with the ruler (one angle on each side of the ruler) are supplementary angles. In the figure below, the two angles are supplementary because 140o + 40o = 180o, a straight line:
A common problem with supplementary angles is one where you are given only one angle and asked to find the supplementary angle to it. This is just 180o - the angle you are given!

Now, here is a problem for you:

What is the measure of angle x? = _______________ degrees.