Question

30.Prove that the area of an equilateral triangle described on one side of a square

is equal to half of the area of the equilateral triangle described on one of its

diagonal.​

Answer 1

Answer:

Given:

ABCD is a Square,

DB is a diagonal of square,

△DEB and △CBF are Equilateral Triangles.

To Prove:

A(△DEB)

A(△CBF)

=

2

1

Proof:

Since, △DEB and △CBF are Equilateral Triangles.

∴ Their corresponding sides are in equal ratios.

In a Square ABCD, DB=BC (1)

∴

A(△DEB)

A(△CBF)

=

4

3

×(DB)

2

4

3

×(BC)

2

∴

A(△DEB)

A(△CBF)

=

4

3

×(BC

2

)

2

4

3

×(BC)

2

(From 1)

∴

A(△DEB)

A(△CBF)

=

2

1