Answer:
1a. E = IR, I = 5, R = 3
E = 5 × 3
E = 15
b. A = πrl, π = 3.14, r = 5, l = 20
A = 3.14 × 5 × 20
A = 314
c. S = 90 ( 2n - 4 ), n = 6
S = 90 ((2 × 6) - 4)
S = 90 ( 12 - 4 )
S = 90 ( 8 )
S = 720
