Question

(1) If the lengths of diagonals of rhombus are 11.2 and 7.5 cm then its area is
(A) 42 sq. cm
(B) 42 cm
(C) 84 sq. cm
(D) 84 cm​

Answer 1

Answer:

A 42 sq.cm

Step-by-step explanation:

Area of rhombus =1/2(product of its diagonals)

= 1/2 ( 11.2* 7.5)

= 1/2 (84)

= 42 cm^2

Answer 2

Answer :

${\boxed{ \bf{ \blue{(A) \: 42 \: cm^2 }}}}$

Given :

• Lengths of diagonals of a rhombus are 11.2 cm and 7.5 cm.

To Find :

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• Area of the rhombus.

Calculation :

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To calculate the area of rhombus, we'll be using this formulae :-

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• $\boxed{ \bf{Area \: of \: rhombus = \dfrac{1}{2} \times d_2 \times d_2}}$

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Where,

⋆ $\sf{d_1}$ (Diagonal 1) = 11.2 cm

⋆ $\sf{d_2}$ (Diagonal 2) = 7.5 cm

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Putting the values,

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$: \Longrightarrow \bf \dfrac{1}{2} \times 11.2 \: \times 7.5 \: cm$

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$: \Longrightarrow \bf \dfrac{1}{2} \times 84 \: cm$

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$: \Longrightarrow { \boxed{\bf{ \purple{42 \: cm ^2}}}} \: \bigstar$

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Therefore, area of the rhombus is 42 cm².

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$\dag$ More Formulae :

• Perimeter of rhombus = $\sf Perimeter = 4 \times Area$

• Area of parallelogram = base × height

• Area of triangle = $\sf \dfrac{1}{2}$ × base × height

• Area of equilateral triangle = $\sf \: \dfrac{\sqrt{3}}{4} \: a^2$

• Height of equilateral triangle = $\sf \: \dfrac{\sqrt{3}}{2} \: a$

• Heron's formulae for calculating the area (triangle) = $\sf \: \sqrt{s(s - a)(s - b)(s - c) \: sq. \: unit}$

• Heron's formulae for calculating the semi perimeter (triangle) = S = $\sf \dfrac{a + b + c}{2}$