Question

A rectangular paper 14cm wide is rolled a long its width to form of cylinder with radius 20cm find the area of rectangle .sheet of paper​

Answer 1

Area of Rectangle is 1760 cm² .

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Explanation :-

Here, Lenght of Rectangular paper is given 14 cm . Radius of Cylinder is 20 cm . And, we have to calculate the Area of Rectangle .

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● First, we will calculate the Breadth :-

\begin{gathered} \Longrightarrow \: \sf{ Breadth = 2 \: \pi \: r} \\ \end{gathered}

⟹Breadth=2πr

\begin{gathered} \Longrightarrow \: \sf{Breadth = 2 \times \frac{22}{7} \times 20 } \\ \end{gathered}

⟹Breadth=2×

7

22

×20

\begin{gathered} \Longrightarrow \: \sf{Breadth = } \frac{880}{7} \\ \end{gathered}

⟹Breadth=

7

880

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● Now, calculating Area of Rectangle :-

\begin{gathered} \Longrightarrow \: \sf{ Area \: _{Rectangle} = Lenght \times Breadth} \\ \end{gathered}

⟹Area

Rectangle

=Lenght×Breadth

\begin{gathered} \Longrightarrow \: \sf{Area \: _{Rectangle} = 14 \times \frac{880}{7} } \\ \end{gathered}

⟹Area

Rectangle

=14×

7

880

\begin{gathered} \Longrightarrow \: \sf{Area \: _{Rectangle} = 2 \times \frac{880}{1} } \\ \end{gathered}

⟹Area

Rectangle

=2×

1

880

\begin{gathered} \Longrightarrow \: \sf{Area \: _{Rectangle} = 1760 \: {cm}^{2} } \\ \end{gathered}

⟹Area

Rectangle

=1760cm

2

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Hence :-

Area of Rectangle = 1760 cm² .

hope it will help you

Answer 2

+ Formulas of Areas: - * Square = (side) * Rectangle = Length x Breadth * Triangle = Base x Height Scalene (s (s - a) (s - b) (s - c) Rhombus: x d₁ × d₂ 1 2 Rhombus = d√4a²d2 Parallelogram = Base x Height Trapezium = (a + b) x Height (a + * Equilateral Triangle = (side)

hope it helps you

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