Verified answer

<1 and <2 are supplementary angles.

<1 and <3 are vertical angles. ..................................... [1]

and

m<2 = 72 degrees,

SO,

<1 = 180 -<2 = 180 - 72 = 108 degrees, ..................... [2]

From [1] & [2], <3 = <1 = 108 degrees >=====================< ANSWER

If m<2 = 72 degrees then m<1 = 180 - 72 = 108 degrees

If <1 and <3 are vertical angles then m<1 = m<3 = 108 degrees.

Angle 3 is supplementary to Angle 2, so angle 3 = 108 degrees