Question

two cones with same base radius 8 cm and height 15 cm are joined together along their bases. find the surface area of the shape formed

Answer 1

look at attachment...,

Answer 2

Surface area of the figure formed = CSA of cone × 2

(Since there are two figures of same size, we will multiply by 2)


Now CSA of cone = πr(l)


We know that l = √(r² + h²)

=> l = √(8² + 15²)

=> l = √(64 + 225)

=> l = √(289)

=> l = 17 cm

So the CSA of cone = πrl

Taking 22/7 as π,

CSA =
$\frac{22}{7} \times 8 \times 17 \\ \\ = > \frac{22}{7} \times 136 \\ \\ = > \frac{2992}{7}$

So CSA of cone = 2992/7 cm²(approx)


=> Surface area of cone = 2 × 2992/7

= 5984/7 cm²

= 854.85 cm² (approx)
or,
854.9 cm² ( approx)



Hope it helps dear friend