Ineed asap (15 points) which of these describes a method in studying plate movements? a)observing absence of magnetic rocks in locations that do not match the poles b)match relief elements only on the western side of the atlantic ocean c) recording the spread of the seafloor in the mid-atlantic region d)correlate the rotation of earth to plate movement

I'm pretty sure there's a geometry rule for   anyways, if the triangle is equilateral, and the circle is circumscribed, the circle is outside of the triangle.  to find the area, you need the radius.  the radius should be a straight line from the center of the triangle to any of it's points.  draw lines from the center of the circle to each of the triangle points.  draw three more lines from the center to the middle of the sides of the triangle.  you should now have six separate 30-60-90 triangles inside of your original triangle. use your 30-60-90 rules to solve for the radius, then the circumference.