The altitude of an equilateral triangle is 7 root 3 units long. The length of one side of the triangle is ____ units.

A. 7
B. 14
C. 14 root 3
D. (7 root 3) /2

Question

The altitude of an equilateral triangle is 7 root 3 units long. The length of one side of the triangle is ____ units. 

A. 7
B. 14
C. 14 root 3
D. (7 root 3) /2

ash2326 · Answer

@angelicapad All sides are equal for an equilateral triangle, altitude for an equilateral triangle is also the median.
So altitude will the half the side. 
See the diagram|dw:1352702635737:dw|
all sides are equal let, them be a
and we have the altitude as $7\sqrt 3$
In triangle ABD
AB=a
AD=$7\sqrt 3$
BD=a/2
ABD is a right triangle, can you find a now?