Mattea was asked to find the measure of an interior angle of a regular octagon. Mattea’s work is shown below. Steps Mattea’s Work Step 1 (n minus 2) 180 degrees = (9 minus 2) 180 degrees Step 2 7 (180 degrees) = 1260 degrees Step 3 1260 degrees divided by 8 = 157.5 degrees Where, if at all, did Mattea first make a mistake finding the measure of an interior angle? step 1 step 2 step 3 Mattea did not make a mistake.