The length of the edge of the regular tetrahedron is ' '

MATHEMATICS · Single correct · CBSE · Mathematics · Vector Algebra · Vector Algebra

Problem

The length of the edge of the regular tetrahedron

ABCD

is '

a

'. Points

E

and

F

are taken on the edges

AD

and

BD

respectively such that '

E

' divides

DA

and '

F

' divides

BD

in the ratio

2:1

each. Then, area of

\Delta CEF

is (1)

\frac{5a}{12\sqrt{3}}

sq units (2)

\frac{a}{12\sqrt{3}}

sq units (3)

\frac{a^2}{12\sqrt{3}}

sq units (4)

\frac{5a^2}{12\sqrt{3}}

sq units