1. c = 12.56 cm high = 8 cm.

2.d= 10cm h=6cm

3.r=6dm h= 10dm

solve

1, c = 12.56 cm high = 8 cm.

Transverse area = ch =12.56× 8 =100.49 (square centimeter)

Bottom area = (12.56÷π) ÷ 2× (12.56÷π) ÷ 2×π.

=6.28÷π×6.28

=39.4384÷π

= 12.56 (cm2)

Surface area = side area+bottom area ×2

= 100.49+ 12.56×2

= 125 438+0 (square centimeter)

2、d= 10cm h=6cm

Transverse area =πdh

=3. 14× 10×6

= 188.4 (square centimeter)

Bottom area = 3.14×10 ÷ 2×10 ÷ 2.

=3. 14×25

=78.5 (square centimeter)

Surface area = side area+bottom area ×2

= 188.4+78.5×2

=345.4 square centimeters

3、r=6dm h= 10dm

Transverse area =2πrh

=2×3. 14×6× 10

=376.8 square centimeters

Bottom area =πrr

=3. 14×6×6

= 1 13.04 (square centimeter)

Surface area = side area+bottom area ×2

=376.8+ 1 13.04×2

=602.88 square centimeters