# Math Help Please

posted by
**Andrew** on
.

The concentric circles, or growth rings, represent the cross-section of a tree with a diameter of 16 centimeters. The width of the outer tree ring measures 2 centimeters. What is the area in square centimeters of the outer ring of the cross-section of the tree? Use 3.14 for p.i.

pi [(8^2) - (7.8)^2]

8 cm is the radius of the outside of the outer ring, and 7.8 is the radius of the inside of that ring.

I have neglected the bark of the tree when considering the radius of the outer ring to equal (tree diameter)/2