2.  P ERIMETER : T HE DISTANCE AROUND A FIGURE  Example  What is the perimeter of the figure below? 12 ft 9 ft 6 ft 18 ft 15 ft 12 ft + 9 ft + 6 ft + 6 ft + 18 ft + 15 ft 66 ft

3.  F ORMULA : A N EQUATION THAT SHOWS HOW CERTAIN QUANTITIES ARE RELATED.  Some figures have special characteristics. For example, because the opposite sides of a rectangle have the same length, we can use a formula to find its perimeter.  P ERIMETER OF A RECTANGLE : P = 2l + 2w  Example: What is the perimeter of the rectangle below? 9 m 5 m P = 2l + 2w P = 2(9) + 2(5) P = 18 + 10 P = 28 The perimeter is 28 m.

4.  A REA : T HE NUMBER OF SQUARE UNITS NEEDED TO COVER ITS SURFACE.  The area of a rectangle can be found by dividing it into 1x1 squares of whatever unit we’re using  A REA OF A RECTANGLE : A = lw 5 m 4 m

5.  Example  Find the area of the rectangle  Find the area of a rectangle with a length of 8.2 meters and a width of 2.4 meters 14 in 10 in The area is 140 square inches 19.68 m 2

6.  The opposite sides of a parallelogram also have the same length. The area of a parallelogram is closely related to the area of a rectangle.  A REA OF A P ARALLELOGRAM : A = bh height base

7.  Example  Find the area of the parallelogram  Find the area of a parallelogram with a height of 6 feet and a base of 8 feet 5.2 in 4 m The area is 20.8 square meters 48 ft 2 4.3 m

8.  Some math problems can be solved by using a formula. Others can be solved by a problem-solving strategy like finding a pattern (section 1) or making a model. No matter the problem, you can always use a four-step plan. 1. Explore the problem 2. Plan the solution 3. Solve the problem 4. Examine the solution

9.  Example  Julia wants to paint two rectangular walls of her bedroom. One bedroom wall is 15 feet long and 8 feet high. The other wall is 12 feet long and 8 feet high. She wants to put two coats of paint on the walls. She knows 1 gallon of paint will cover about 350 square feet of surface. Will one gallon of paint be enough? Wall one is 15 by 8 feet. What is the area? Wall two is 12 by 8 feet. What is the area? How much paint is needed to give two coats? Can Julia paint both walls twice? 120 ft 2 96 ft 2 432 ft 2 No

10.  Assignment  Worksheet