Question

a conical hole is drilled in a circular cylinder of height 15 cm and radius 8 cm which has same height and same base radius find the total surface area after drilling of home take Pie value 3.14

Answer 1

HELLO DEAR,


height of CYLINDER= height of cone = 15cm

and radius= 8cm

slant height=
$l = \sqrt{ {r}^{2} + {h}^{2} } \\ = > l = \sqrt{ {8}^{2} + {15}^{2} } \\ = > l = \sqrt{64 + 125} \\ = > l = \sqrt{289} \\ = > l = 17cm$


total surface area of cone

= πr(l+r)
$\frac{22}{7} \times 8 \times (17 + 8) \\ = > \frac{4400}{7} \\ = > 628.57c {m}^{2}$
I HOPE ITS HELP YOU DEAR,
THANKS