Question

Curved surface area of a cone is 251.2 cm² and radius of its base is 8cm. Find its slant height and perpendicular height. (???? = 3.14 )

Answer 1

Answer:

Slant height = 10cm

perpendicular height = 6cm

Step-by-step explanation:

Given:

Curved surface area of the cone = $251.2{ cm}^2$

radius of its base = 8cm

Curved surface area of a cone = $\pi rl$

$251.2 = 3.14 \times 8 \times l$

251.2 = 25.12 × l

$l = \dfrac {251.2}{25.12}\\l =10cm$

Slant height = 10cm

Now we have to find perpendicular height

$l^2 = r^2 + h^2\\{10}^2 = 8^2 + h^2\\100 = 64 +h^2\\100 - 64 = h^2\\36 = h^2\\h = 6$

perpendicular height = 6cm