Prove that in an equilateral triangle, three time the square of a side is equal to four time the square of its altitude.
Let side of an equilateral triangle = a,
We kno that,In equilateral triangle of side
a, the altitude of triangle
=√3a2
∴ 4 x The square of altitude =4×(√3a2)2=3a2= three times square of a side.
Hence proved.