The surface area, I believe, is 584,064.
Broken down, the formula is really 312 x 312 x 6
312 x 312 = 97,344 97,344 x 6 = 584,064......... There is your answer.
SA = 584,064
A- scalene would be the answer as a scalene triangle has 3 unequal sides.
Complementary angles add to 90 degrees
A) 40 +c = 90
subtract 40 from each side
40+c -40 = 90-40
c = 50
The complement is 50 degrees
B) 26 +c = 90
subtract 26 from each side
26+c -26 = 90-26
c = 64
The complement is 64 degrees
6 is the answer to the problem sorry it took so long