Answer:
Step-by-step explanation:
4) d = 12 cm; r = 12/2 = 6cm ; h = 5 cm
S.A = 2πr(r + h)
= 2* 3.14 * 6 * (6 + 5)
= 2 * 3.14 * 6 *11
= 414.48 cm²
5) d = 8 cm ; r = 8/2 = 4cm ; h = 7cm
S.A = 2πr(r + h)
= 2 *3.14 * 4 * (4 + 7)
= 2 * 3.14 * 4 * 11
= 276.32 cm²
6) r = 4 cm ; h = 6cm
SA = 2πr(r +h)
= 2 * 3.14 * 4 * 10
= 251.2 cm²
7) Area of front and back = [tex]2*\frac{1}{2}*base * height[/tex]
= base * height
SA = (front and back) + Base + left + right
= 4* 3 + (8*3) + (8*4) + ( 8*5)
= 12 + 24 + 32 + 40
= 108 cm²
8) SA = (front and back) + Base + left + right
= (8 * 6) + (12*6) + (12*8) + (12*10)
= 48 + 72 + 96 + 120
= 336 cm²
9) SA = (front and back) + Base + left + right
= (12 *5) + (8*5) + (8*12) +(8*13)
= 60 + 40 + 96 + 104
= 300 cm²
