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ABC and BDE are two equilateral triangles such that D is the mid-point of BC. Then ar (BDE) = 14 ar (ABC).

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Question

ABC and BDE are two equilateral triangles such that D is the mid-point of BC. Then ar (BDE) = `1/4` ar (ABC).

Options

  • True

  • False

MCQ
True or False
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Solution

This statement is True.

Explanation:

Given: ΔABC and ΔBDE are two equilateral triangles.

Suppose that each sides of triangle ABC be x.

Similarly, D is the mid-point of BC.

So, each side of triangle BDE is `x/2`.

Now, `(Area(ΔBDE))/(Area(ΔABC)) = (sqrt(3)/4 xx (x/2)^2)/(sqrt(3) / 4 xx x^2)`

= `x^2/(4x^2)`

= `1/4`

Therefore, area (ΔBDE) = `1/4` area (ΔABC).

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Chapter 9: Areas of Parallelograms & Triangles - Exercise 9.2 [Page 88]

APPEARS IN

NCERT Exemplar Mathematics Exemplar [English] Class 9
Chapter 9 Areas of Parallelograms & Triangles
Exercise 9.2 | Q 4. | Page 88

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