Presentation on theme: "The Rectangle Method Finding Area of Triangles and Parallelograms."— Presentation transcript:
The Rectangle Method Finding Area of Triangles and Parallelograms
A 30 Second Look-See Find something in the room shaped like: a hexagonal prism a cylinder a quadrangle a cube
Math Journal page 315 Read the top of page 315 Your job will be to think of ways to find the areas of the triangles – I am not interested in the answer. I am interested in the methods you and your partner discover.
Rectangle Method This is called the rectangle method because rectangles are used to surround the figure or parts of the figure. All of the areas that are calculated are either areas of rectangles or of triangular halves of rectangular regions.
Determine the areas of the three shapes and add the parts. 1 x 6 = 6 6 ÷ 2 = 3 = 3 units
Determine the areas of the three shapes and add the parts. 6 x 4 = 24 units
3 + 3 + 24 = 30 units = 3 units 24 units = 3 units
Review your work Return to page 315. Find the area of triangle #3 by splitting the parallelogram into two right triangles and a rectangle. Use the add the parts method to find the area of the complete parallelogram.