Question

7. 'प्रकृति यहाँ एकान्त बैठि, निज रूप सँवारति,
पल-पल पलटति, छलक छन छन छवि धारति,
मानों जादू भरी, विश्व बाजीगर थैली,
खेलत में खुल परी)शैल के सिर फैली।'
उपर्युक्त पंक्तियाँ किस पाठ में आई हैं ?​

Answer 1

Given

The radius and slant of height of a cone are in the ratio 4:7

Curved Surface Area is 792 cm²

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To Find

The radius

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Solution

Let's consider the radius to be '4x' and height be '7x' (Here we have taken the radius as 4x and 7x since they are in the ratio of 4:7)

Formula to find the curved surface area of a cone ⇒ πrl

Here,

'r' stands for radius.

'l' stands for the slant height.

Curved surface area of the cone ⇒ 729 cm²

Let's solve the equation step-by-step

$\sf \dfrac{22}{7} \times 4x \times 7x = 792$

Step 1: Simplify the equation.

⇒ $\sf \dfrac{22}{7} \times 4x \times 7x = 729$

⇒ $\sf \dfrac{22}{7} \times 28x^{2} = 792$

⇒ $\sf 22\times 4x^{2} =792$

⇒ $\sf 88x^{2} = 792$

Step 2: Divide 88 from both sides of the equation.

⇒ $\sf \dfrac{88x^{2}}{88} = \dfrac{792}{88}$

⇒ $\sf x^{2} = 9$

Step 3: Find the square root of 9.

⇒ $\sf x = \sqrt{9}$

⇒ $\sf x = 3$

∴ The radius ⇒ 4x ⇒ 4(3) ⇒ 12 cm

∴ The slant height of cone ⇒ 7x ⇒ 7(3) ⇒ 21 cm

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