2.( 1) has at most one right angle. If there are two, the sum of internal angles is equal to 180 degrees, and the other angle exceeds 180 degrees.

(2 has an obtuse angle, otherwise it will exceed 180 degrees.

(3) no.

3. Angle B60 degrees, angle C70 degrees

4. The angle BAC is equal to 70 degrees.

5.85 degrees

6. Angle C=22.5 degrees

7. Angle C=85 degrees

8. 180 90 180 90

9.360