Andy constructed a triangle angle 1 and 2 are the same but angle 3 has a measurement of 100 degrees what is the measurement of angle 1 and 2

The triangle has one angle of 100 degrees, and the other two are equal. 
We know that the angles of a  triangle always add up to 180. To find the measurement of angle 1 and 2, let's solve for this equation. 
2x + 100 = 180, where x=angle 1 = angle 2. Subtract 100 from both sides
2x = 80                                                           Divide both sides by 2
x = 40