Can you help me with this indirect proof for geometry?

Question

Ok so I need help understanding how to do indirect proofs. I'm so confused. :/

Given: quad. EFGH in which m. of angle EFG=93; m. of angle FGH=20; m. of angle GHE=147; m. of HEF=34
Prove: EFGH is not a convex quad


My teacher wants it in a 5 listed proof exactly like this:
1. Assume temporarily that....
2.Then....
3.But this contradicts the known or given fact that...
4.Therefore are temporary assumption that... .... is false.
5. It follows that...

PLEASE if you are nice and are good at indirect proofs AIM me, my SN is xreactions. PLEASE HELP, Thanks

Answer 1

(1) Let all of those angles equal what you said and assume (for the sake of contradiction) that EFGH -IS- a convex quad.

(2) then the sum of all four interior angles has to be 360. (this is true for any convex quad)
..
but 93 + 20 + 147 + 34 does not equal 360

(3) This contradicts the fact that the sum = 360

(4) Therefore the temp. assumption is false

(5) EFGH is not convex


Sorry.. dont have aim

Answer 2

Indirect proofs are proofs by contradiction. We assume that opposite statement is true and draw conclusions from it. If the conclusions are incorrect, we can reject the opposite statement which is the same as accepting the original statement.

Your statement may have an error. Since all interior of a quad is 360 deg, if HEF is an angle, it can't be a 34 deg. angle. The "Great" Lebowski has the proof, but what he proves is the figure can't be a QUAD. If it can't be a quad, it certainly can't be a convex quad (or even a concave one).