1, SA, SB and SC are perpendicular to each other, and the projection of oblique line CB on plane SAB is SB, so the angle between BC and plane SAB is ∠SBC=60 degrees.

2.SA is perpendicular to SB, so SAB is a right triangle with angle SAB=45 degrees, so SAB is an isosceles right triangle, and M is the midpoint of AB, so SM is perpendicular to AB, and angle SCM is the angle formed by SC and plane ABC. In the right triangle SAB, let AB=a, then SM=a/2 and SB= root number 2a/2.