The altitude of the triangle is \(\displaystyle \dfrac{\sqrt{3}}{2}b\) where \(\displaystyle b\) is the base. You should see that the base is one-half the length of the entire square in your drawing.
hi MarkFL,
this is my working n may I know if it is correct?
i divided the 1/4 of the picture to further 4 by 4 and this is my working...
area of square is 6*6=36
area of green triangle is 1/2 *4.5*6= 13.5
Area of "what it looks like 2 slices of pizzas = 1/2 * 6* 3 *2= 18
so.....
Area of tiny shaded part is 36-18-13.5=4.5...??