Triangle ABC is shown below:
Given: ΔABC

Prove: All three angles of ΔABC add up to 180°.

The flowchart with missing reason proves the measures of the interior angles of ΔABC total 180°:

Which reason can be used to fill in the numbered blank space?

Alternate Exterior Angles Theorem

Same-Side Interior Angles

Corresponding Angles Postulate

Alternate Interior Angles Theorem

Question

Triangle ABC is shown below:
Given: ΔABC 

Prove: All three angles of ΔABC add up to 180°.

The flowchart with missing reason proves the measures of the interior angles of ΔABC total 180°:

Which reason can be used to fill in the numbered blank space?

 Alternate Exterior Angles Theorem
 
Same-Side Interior Angles
 
Corresponding Angles Postulate

 Alternate Interior Angles Theorem

hansc · Answer

attachment

hansc · Answer

attachment

hansc · Answer

Please help??

hansc · Answer

@TheSmartOne  thanks.. this is the link..

jhonyy9 · Answer

@hansC are you here please ?

hansc · Answer

yess.. @jhonyy9

jhonyy9 · Answer

ok- thank s so  i like help you - ok. ? 

looke please than you check the angles <EBC and <BCA what you see - what was the reason that are congruent ?

jhonyy9 · Answer

alternate ... what ?

jhonyy9 · Answer

do you see it on gif3 have wrote there

jhonyy9 · Answer

alternate interior angles - yes ?

jhonyy9 · Answer

@hansC do you see it ? so than yes what is your opinion about <DBA and <BAC ? not are same angles ?

hansc · Answer

alternate interior theorem @jhonyy9

hansc · Answer

yess it should be it cause its not the same.. @jhonyy9

jhonyy9 · Answer

but than you check them are the same angles alternate interior - so this is the missed part sure

hansc · Answer

ohh okayy.. thank you so much @jhonyy9

jhonyy9 · Answer

np

was my pleasure and any time 

bye bye