Hey can you me posted picture of question : )

Atriangle has a side lengths of 18cm, 80 cm and 81cm. classify it as acute obtuse or right?

*let m∠cob = 50°30’, m∠aob = 70° and m∠aoc = 20°30’. could point c be in the interior of ∠aob? why? a. point c could be the interior of aob but it is not the only case b. point c is the interior of aob c. point c is not the interior of aob d. the given is not possible for the plane geometry answer

What is the missing reason in the proof? segment addition congruent segments theorem transitive property of equality subtraction property of equality?