Answer:
123 Degrees.
Explanation:
This is basically the Exterior Angle Theorem which basically states that the exterior angle (m<1) is equal to the sum of the 2 opposite interior angles. (60 & 63).
Following this theorem your equation should look something like this -
Exterior Angle = Opposite Interior Angle + Opposite Interior Angle.
Plug in the numbers and you'll get -
m<1 = 60 + 123
m<1 = 123
