Question

PROOF. Can you tell me how "Supplement of an obtuse angle is acute" can be proven?

Answer 1

I know what it means, yet I want you to give me a way

Answer 2

on how to write proofs

Answer 3

Will an example do?

Answer 4

Yes, it will. @AnImEfReaK :)

Answer 5

Let x be the obtuse angle.
x > 90 degrees
180 - x < 180 - 90
180 - x < 90 degrees
Thus, the supplement of an obtuse angle is an acute angle.
You need to change the greater than sign to lesser than because you changed the positive signs of x and 90 degrees to negative.

Answer 6

Supplementary angles add up to 180 degrees. In this case imagine an angle of 100 degrees, which is obtuse as it is 90>. 180-100= 80 so its supplement is 80 degrees. 80 is <90 therefore this angle is acute.

Answer 7

thank you guys. :)

Answer 8

Your welcome :)