express area of equilateral triangle as function of one side s???
Let h = height of triangle. Then h=s*sin60 So area= 1/2*s*s*sin60=1/2*s^2*sin60 Sin60=root3/2 so area = root3*s^2/4
Can get the height by 'splitting' triangle in two and using Pythagoras, if you prefer.