In any polygon with number of sides = n, the sum of measures of its internal angles is equal to (n-2)*180
Now, for a nonagon: number of sides = 9 sum of internal angles = (9-2)*180 = 1260 degrees
We are given the measures of seven of its angles and we know that the other two are equal. Assume that each angle of the remaining two angles has a measurements = x degrees
Therefore: sum of angles = 138 + <span>154 + 145 + 132 + 128 + 147 + 130 + x + x 1260 = 974 + 2x 2x = 1260 - 974 2x = 286 x = 143 degrees
Based on the above calculations: The measure of each angle of the remaining two angles is 143 degrees</span>
