If two angles of a triangle are 30 and 102 what is the third angle

If you add all three interior angle measures together in a triangle it will always equal 180°.. To find a third angle you will subtract the sum of the two given angles from 180°. Look at the 3 examples below.

Now let's look at what to do when we are given 2 angles but we are missing the 3rd angle.

Example 1:

Example 2:

Example 3:

The key to finding the missing angle measure of a triangle is to remember that the sum of the interior angles of any triangle is always 180°. If you know 2 angles then you can subtract their sum from 180° to find the measure of the 3rd angle.