**Concept:**

**Concept:** Intro

**Problem:** Mike wants to build a rectangular pen with the using two parallel partitions and 600 feet of fencing. What dimensions will maximize the total area of the pen?

**Problem:** Mary needs to make an open rectangular box with square base from 48 ft.^{2} of material. What dimensions will result in a box with the largest possible volume?

**Problem:** Marcio is a farmer with 600 ft of fencing that wants a rectangular field that borders a river. What are the dimensions of the field that has the largest area?