Question

A right angle triangle of base 4 cm
and height 3 cm is revolving about its
height. The surface area and volume
of obtained solid figure are
respectively.​

Answer 1

the solid figure obtained will be a cone

height of cone = 3cm

base =4cm = radius

The volume of a cone = (1/3) πr2h cubic units

Where,

‘r’ is the base radius of the cone

‘l’ is the slant height of a cone

‘h’ is the height of the cone

volume = ⅓ × 22/7 × 4² × 3

= 50.28 cubic units

total surface area of cone = πr (l+r)

l = √ r²+ h²

= √ 16+9 =√25 = 5 cm

TSA = 22/7×4 ( 5+4)

22/7×4×9

= 113.14