1 / 23

Area

Area. of a. Trapezoid. Area of a Triangle. Today we are going to review Area of a Triangle & Parallelogram. Then we are going to discover the Area of a Trapezoid. Area of a Triangle.

akio
Download Presentation

Area

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Area of a Trapezoid

  2. Area of a Triangle Today we are going to review Area of a Triangle & Parallelogram. Then we are going to discover the Area of a Trapezoid.

  3. Area of a Triangle Given the formula for area of a rectangle, we are going to use that information to discover the formula for the area of a triangle. Watch carefully not to miss it!

  4. Area of a Triangle Given a right triangle Make a similar triangle,

  5. Area of a Triangle Given a right triangle What polygon is this? A Rectangle Make a similar triangle, and put both triangles next to each other flip it

  6. Area of a Triangle We can use the formula for area of a rectangle to find the formula for area of a triangle. Twotriangles make one rectangle. We want to find half of the area of the rectangle. height h base b Whatis the formula for the area of a triangle?

  7. height h base Area of a Triangle This holds true for any triangle

  8. Area of a Triangle A triangle is half the area of a rectangle. To find the area of a triangle, you use the rectangle formula (base times height) and divide it in half. A = base •height 2 13 m 12 m 5 m A = 5 • 12 = 30 m2 2

  9. Area of a Triangle Find the perimeter and area of this triangle. Area 5 cm 8 cm 3 cm 11 cm Perimeter P = a + b + c P = 5 + 8 + 11 P = 24 cm

  10. Area of a Trapezoid Given the formula for area of a triangle and the formula for area of a parallelogram we are going to use that information to discover the formula for the area of a trapezoid Watch carefully not to miss it!

  11. Area of a Trapezoid This trapezoid is regular. regular trapezoid Also known as an isosceles trapezoid This trapezoid is an irregular trapezoid. irregular trapezoid

  12. h (b1 + b2) b1 h b2 Area of a Trapezoid b1 What polygon is it now? h Parallelogram b2 Give the height, base 1 & base 2 Copy that trapezoid, flip it over, and put it next to the original

  13. h (b1 + b2) Area of a Trapezoid put together with a similar flipped trapezoid, we found it made a parallelogram. Given our original trapezoid We are going to use the area of a parallelogram to find the area of a trapezoid. Notice that the trapezoid is half the area of the parallelogram. It takes two trapezoids to make one parallelogram.

  14. h (b1 + b2) Area of a Trapezoid Notice that the trapezoid is half the area of the parallelogram. How do we find half the area? Hint: Think of area of a triangle. Trapezoid Parallelogram A = (b1 + b2) • h 2

  15. Area of a Trapezoid Area of Trapezoid 2 in 4 in A = (b1 + b2) •h 3 in 2 6 in = 12 in2

  16. Area of a Trapezoid Area of Trapezoid 3 m 5 m A = (b1 + b2) • h 4 m 2 8 m = 22 m2

  17. Area of a Trapezoid 5 in 4 in 6 in 7 in Here is another way to look at the trapezoid formula. Instead of dividing by 2, multiply by ½

  18. Area of a Trapezoid The End! Take out your study guide!

  19. Area of a Trapezoid # 5 4 ft A = (base1 + base2) x height 3 ft 2 A = (b1 + b2) x h 5 ft 2 A = (4 + 5) x 3 2 A = (9) x 3 27 = 13.5 ft2 = 2 2

  20. #6 Area of Polygons The Areaof a figure is the number of square units needed to cover it. Parallelogram Rectangle Triangle 7 4 8 7 5 5 10 8

  21. If you have trouble viewing you need MathType software: To see all math formulas correctly you need to install MathType software, similar to equation editor and is available for free at Design Science website.

  22. For more information on Math Slideshows visit:http://www.mathslideshows.com/

  23. If you downloaded this please vote for me! I am new on TpT.I have over 175 Math Slideshows available at my website:http://www.mathslideshows.com/

More Related