In ΔABC, m∠A = 40°, m∠B = 60°. Find m∠C. (Hint: Draw the auxiliary line BD parallel to the line segment AC and take a look at the same side and the alternate interior angles)

Question

I NEED HELP! This geometry question is hard, and I have another one afterwards.

Given: 

AB

 ⊥ l, B ∈l, M ∈ 

AB

 , AM = 7 in, AB = 15 in. Find the distance between point M and line l.

HELP!

Answer 1

I don't understand the hint!

If ∠A = 40 degrees and ∠B = 60 degrees and ∠C is the third angle in the triangle, then ∠C must be 100 degrees since the sum of th angles in a triangle is 180 degrees.

Of course the hint is the way you prove that the sum of the angles in a triangle is 180 degrees (and note that you have used the parallel postulate to prove this).