Problem: the diagonal of a square is the height in an equilateral triangle . if the side of the square is x , what is the side of the equilateral triangle in terms of x ? 
Options: ['a ) √ ( 2 / 3 ) × x', 'b ) 2 / √ 3 × x', 'c ) √ 3 x', 'd ) √ ( 8 / 3 ) × x', 'e ) 2 √ 3 × x']
d