The volume of a cone is 1/3 pi r^2 h. So by substitution, V = 1/3 of 80pi which simplifies to V=26.667pi, which when multiplied out, provides the answer V = 83.8 cubic meters.
Draw a number line with 10 positives and 10 negatives. Count from 0 to 8. Now, from 8, count back 12 spots. From that spot, go back to 0, which is their original position. The number you counted there is your answer.
