Question

The measure of angle 1 is: The measure of angle 1 is:

Answer 1

Question 1:
We can use the rule of exterior angle of triangle, where the exterior angle is equal to the sum of the other 2 interior angles of the triangle except for the adjacent one.

So, we can calculate angle 1 by adding up the 2 given angles.
Angle1 = 62° + 57°
=119°
=answer C.

Question 2:
We can also apply the rule above, but first we have to calculate the remaining angle of the triangle first.
For this, we have to use the angle sum of triangle. All 3 interior angles of triangle should add up to 180°.

Let that remaining angle be x.
X = 180° - 62° - 57°
X=61°
Now we can apply the rule of exterior angle of triangle.
Angle 1 = 62° + 61°
=123°
=answer D.