D. 7.2lbs To find the range all you have to do is subtract the smallest number from the group from the biggest number. And in this case that would be 9.9- 2.7
1: 8 faces and 9 with the base 9 vertices and 16 edges
2: 3 faces and 5 with the bases 6 vertices and 9 edges
3: 3 faces and 4 with the base 4 vertices and 6 edges
The relevant formula for the area of the triangle is
.. A = (1/2)ab*sin(C)
.. = (1/2)*(2.75 mi)*(1.32 mi)*sin(35°)
.. ≈ 1.04 mi^2
The 4th selection is appropriate.