The measure of the seven angles in a nonagon measure 138, 154, 145, 132, 128, 147 and 130. if the two remaining angles are equal in measure, what is the measure of each angle

To find the missing two angle measures, you will need to know that the sum of all nine angles in a nonagon equal 1260 degrees.

Knowing this, you can use this total to find the missing congruent angles.

Start with the total and subtract what you know. Divide what is left by two to get each angle measure.

1. 1260 - (138 + 154 + 145 + 132 + 128 + 147 + 130) = 286

2. 286/2 = 143

The missing angles are each 143 degrees.