(Solved): The diameter of a tree was 16 in. During the following year, the circumference increased 4 in. Abou ...

The diameter of a tree was 16 in. During the following year, the circumference increased 4 in. About how much did the tree's diameter increase? About how much did the tree's cross-section area change? The tree's diameter increased by in. (Simplify your answer. Type an integer or decimal rounded to four decimal places as needed.) The estimated change in area is in.². (Simplify your answer. Type an exact answer. Type an integer or a decimal.)