**Problem 29**

A certain Chinese coin, 1/2 in. in diameter and 1/16 in. thick, is pierced by a square hole 1/8 in. on a side. Find the amount of metal in a coin.

**Solution 29**

$A_b = A_{circle} - A_{square} = \frac{1}{4}\pi(\frac{1}{2})^2 - (\frac{1}{8})^2$

$A_b = 0.1807 ~ \text{in.}^2$

$V = A_bh = 0.1807(\frac{1}{16})$

$V = 0.011\,295 ~ \text{in.}^3$ *answer*