Despite its dangers, volcanic activity has benefited japan by creating
a. hot springs
b. longer growing seasons
c. fertile soil
d. geothermal energy

The best and most correct answer among the choices provided by the question is the fourth choice. Geothermal energy benefited Japan by transforming heat energy to electrical energy to be consumed by homes and industries. I hope my answer has come to your help. God bless and have a nice day ahead!

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. 

A,b,c is the answer to the question