one math question?

Question

A triangle with interior angles labeled 1,2, and 3. The exterior angle at 3 is labeled angle 4. Complete the following proof. Fill in for number 2, 3 5, 6, and 7.

here is a picture of what i see

http://i1.tinypic.com/4xkv7m9.jpg

Answer 1

Since the sum of the interior angles = 180 and m3 and m4 = 180, then m1+ m2+m3 = m3 + m4

thus m1 + m2 = m4

Answer 2

Okay.

a: Angles in a triangle add up to 180 degrees.
b: Since angle 4 is an exterior angle to angle 3, they are linear.
c: If two angles are supplementary, they add up to 180 degrees.
d: As angle 1, angle 2 and angle 3 add up to 180 degrees, and angle 3 and angle 4 also add up to 180 degrees, one can substitute either one of the equations into the other.
e: Since both sides have a "+angle 3" in them, one may subtract them from each side.

Hope that helped!