i can tell you how to work out 3)
so each side is 4 since 12÷3=4.
to work out the area you need the perpendicular height (line that goes through the middle of the triangle).
to do this you need SOHCAHTOA.
so in this case you use sine and angle is 60 since its an equilateral
sin 60=×÷4
x=sin 60 × 4
