Lesson 29 Area of a Combined Figure

Get the Idea Sometimes, you need to find the area of a figure that is not a common shape. You can often do this by dividing that figure into familiar shapes, such as triangles, rectangles or circles. The formulas for finding the area of triangles, rectangles or circles will be provided for you on the NJAsk Reference Sheet

Example 1 This is the floor plan of the dining room n a new house. The dining room is rectangular with another rectangular area near one end. How many square feet of wood flooring would be needed to completely cover the floor in this room? 12 ft 18 ft 15 ft

Strategy Divide the figure into two shapes. Then find the area of each. 12 x 12= 144 and 6x15= = 234 sq.ft 12 ft 15 ft 12x12 Total: 18 ft 6 ft 6x15

Example 2 This is a sketch of a park near McHenry School. Find the area of the park. How would I cut this shape up? 50 ft 30 ft

How we cut it up… Divide the figure into two shapes. Then find the area of each. Square: 50x50= 2500 Triangle: ½(50x30)= ½ (1500)= = 3250 sq ft. 50 ft 30 ft 50 x50 ½(50 x30)

One more together What is the total area of the figure below? Draw a line to divide the figure above into a ¼ circle and a square. How do I find the area of a ¼ circle? What do I do to find the total area of the shape? 10m