Lesson objective: Apply formulas to find area, perimeter, and the measure of a missing side.
This lesson provides an opportunity for students to apply their knowledge and understanding of area and perimeter to a reallife situation. Students are asked to help figure out the dimensions of a new petting zoo.
Key Concept students will use:
 We can use the relationship between multiplication and division to solve mathematical and realworld problems.
Skills students will use:

Find the area of a rectangle (with whole number length sides) by tiling it with unit squares or by multiplying the side lengths. (Grade 3, Unit 2, 3.MD.C.7.a)
 Use division to solve for the missing side when given the area and length or width of a rectangle.
Students engage in Mathematical Practice 1 (Make sense of problems and persevere in solving them) as they make connections to prior knowledge to find an entry point.
Students engage in Mathematical Practice 8 (Look for and express regularity in repeated reasoning) as they connect principles of operations to efficiently solve a multistep problem.
Key vocabulary:
 area
 perimeter