41
It is: 180-42 = 138 degrees
8.57 degrees
The third angle measures 18 degrees.
The 42 interior angles of a regular 42-agon add up to 7200 degrees and each angle is 7200/42 which is 171.'428571' degrees recurring decimal '428571'
180 - twice 42
41
It is: 180-42 = 138 degrees
90 - 42 ie 48o
The vertex angle of an isosceles triangle is equal to the measure of each of its base angles. Therefore, if one of the base angles measures 42 degrees, then the vertex angle also measures 42 degrees.
69 degrees 180-42 = 138 138/2 = 69 degrees You do not need the measure of the side to derive the answer.
8.57 degrees
42
171.428571 degrees (recurring decimal)
Each interior angle measures 1710 25' 42.86''
21 degrees
The third angle measures 18 degrees.