Using the sum of the internal angles of a triangle and supplementary angles, it is found that the measure of angle 1 is of 121º.
What is the sum of the internal angles of a triangle?
The sum of the three internal angles of a triangle is of 180º.
Hence, the measure of the remaining interior angle is given by:
60º + 61º + x = 180º
x = 59º.
What are supplementary angles?
Two angles are supplementary if the sum of their measures is of 180º.
An interior angle is supplementary with it's respective exterior angle, hence:
m<1 + 59º = 180º
m<1 = 121º.
The measure of angle 1 is of 121º.
More can be learned about supplementary angles at https://brainly.com/question/12919120
