2) right

3) equiangular

4) acute

5) scalene

6) equilateral

7) isosceles

8) always true

9) never true

10) never true

11) triangle ABC = triangle DEF and AB = BC - Given

AB = DE and BC = EF - CPCTC

DE = EF - Substitution

12) AB = DE and DF = AC and angle A = angle D - Given

triangle ABC = trianlge DEF - SAS

BC = EF - CPCTC

13) triangle ABC = triangle DEF - Given

angle A = angle D and angle B = angle E - CPCTC

angle A + angle B = angle D + angle B - addition