Question

(approx.).
Hence
height of the cone.
: We have,
Example 4: The curved surface area of a cone is
3080 cm2 and its radius is 28 cm. Determine the slant height of the cone​

Answer 1

Answer

The slant height of the cone is 35cm

Explanation:

Given:

• The curved surface area of a cone = 3080 cm²
• The radius of the cone = 28cm

To Find

• Slant height of the cone.

Curved surface area of a cone = πrl

• r = radius
• l = slant height

⟹ 3080cm² = π ( 28cm ) ( l )

⟹ 3080cm²/28cm = πl

⟹ 110cm = πl

⟹ 110cm = 22/7 × l

⟹ 110cm × 7/22 = l

⟹ 35cm = l

The slant height of the cone is 35cm

More:

Cone is 3-d shape with its base as circle and every point on its diameter meets at a common point. A party hat resembles a cone.

volume = 1/3 × πr²h

Surface area = πr² + πrl

Curved surface area = πrl

Answer 2

Answer:

Given:-

In a cone

$\sf Curved\:Surface\:Area{}_{(CSA)}=3080cm^2$

$\sf Radius{}_{(r)}=28cm$

To find:-

$\sf Slant\:height{}_{(l)}$

Solution:-

As we know that in a Cone

$\boxed{\sf Curved\:Surface\:Area{}_{(CSA)}=\pi rl}$

• Substitute the values

${:}\rightarrowtail$$\sf 3080=\dfrac {22}{\cancel{7}}\times \cancel {28} \times l$

${:}\rightarrowtail$$\sf 3080=22\times 4l$

${:}\rightarrowtail$$\sf 88l=3080$

${:}\rightarrowtail$$\sf l=\dfrac {3080}{88}$

${:}\rightarrowtail$$\sf l=35cm$

$\therefore\underline{\sf Slant\:height\:of\:cone\:is\:35cm.}$

Extra information:-

Cone:-

• Cone is a 3-d(3-dimensional)shape.
• It has a circular base .
• Every points started from the diameter of its base meet at a single point called vertex (Apex).
• Example :-Christmas tree,Funnel

Some formulas related to cone:-

$\boxed{\begin{minipage}{6 cm}\sf {\textcircled{\footnotesize\textsf{1}}} \:Area\:of\:Base =\pi r^2 \\\\ \sf {\textcircled{\footnotesize\textsf{2}}} \:\:Curved \: Surface \: Area = \pi rl\\\\\sf{\textcircled{\footnotesize\textsf{3}}} \:\:TSA = \pi r^2+\pi rl\\ \\{\textcircled{\footnotesize\textsf{4}}} \: \:Volume=\dfrac{1}{3}\pi r^2h\\ \\{\textcircled{\footnotesize\textsf{5}}} \: \:Slant \: Height=\sqrt{r^2 + h^2}\end{minipage}}$