posted by DANIELLE on .
Writing indirect proofs.
Can someone please check for me. I am not sure If this is correct.Thanks much
Given: triangle ABC angle B=120 degree
Proof: Triangle A does not equal 60 degree
Plan: Using an indirect proof, using the paragraph method
Assume temporarily that Measure angle A = 60. Then measure angle C=60,
and measure angles A+B+C=180= 60+B+60=180. Therefore the temporary assumption that measure angle A=60 is false. It fallows that measure angle 60 does not equal 60 degrees