Area Formulas
- 1.
- 2.
- 3. Rectangle What isthe area formula?
- 4. Rectangle What isthe area formula? bh
- 5. Rectangle What isthe area formula? bh What other shape has 4 right angles?
- 6. Rectangle What isthe area formula? bh What other shape has 4 right angles? Square!
- 7. Rectangle What isthe area formula? bh What other shape has 4 right angles? Square! Can we use the same area formula?
- 8. Rectangle What isthe area formula? bh What other shape has 4 right angles? Square! Can we use the same area formula? Yes
- 9. Practice! Rectangle Square10m 17m 14cm
- 10. Answers Rectangle Square10m 17m 14cm 196 cm 2 170 m 2
- 11. So then whathappens if we cut a rectangle in half? What shape is made?
- 12. Triangle So thenwhat happens if we cut a rectangle in half? What shape is made?
- 13. Triangle So thenwhat happens if we cut a rectangle in half? What shape is made? 2 Triangles
- 14. Triangle So thenwhat happens if we cut a rectangle in half? What shape is made? 2 Triangles So then what happens to the formula?
- 15. Triangle So thenwhat happens if we cut a rectangle in half? What shape is made? 2 Triangles So then what happens to the formula?
- 16. Triangle So thenwhat happens if we cut a rectangle in half? What shape is made? 2 Triangles So then what happens to the formula? bh
- 17. Triangle So thenwhat happens if we cut a rectangle in half? What shape is made? 2 Triangles So then what happens to the formula? bh 2
- 18. Practice! Triangle 5ft 14 ft
- 19. Answers 35 ft2 Triangle 5 ft 14 ft
- 20.
- 21.
- 22.
- 23. Summary so far...bh bh
- 24. Summary so far...bh bh 2
- 25. Parallelogram Let’s lookat a parallelogram.
- 26. Parallelogram Let’s lookat a parallelogram. What happens if we slice off the slanted parts on the ends?
- 27. Parallelogram Let’s lookat a parallelogram. What happens if we slice off the slanted parts on the ends?
- 28. Parallelogram Let’s lookat a parallelogram. What happens if we slice off the slanted parts on the ends?
- 29. Parallelogram Let’s lookat a parallelogram. What happens if we slice off the slanted parts on the ends?
- 30. Parallelogram Let’s lookat a parallelogram. What happens if we slice off the slanted parts on the ends?
- 31. Parallelogram Let’s lookat a parallelogram. What happens if we slice off the slanted parts on the ends?
- 32. Parallelogram Let’s lookat a parallelogram. What happens if we slice off the slanted parts on the ends?
- 33. Parallelogram Let’s lookat a parallelogram. What happens if we slice off the slanted parts on the ends?
- 34. Parallelogram Let’s lookat a parallelogram. What happens if we slice off the slanted parts on the ends?
- 35. Parallelogram Let’s lookat a parallelogram. What happens if we slice off the slanted parts on the ends?
- 36. Parallelogram Let’s lookat a parallelogram. What happens if we slice off the slanted parts on the ends? What will the area formula be now that it is a rectangle?
- 37. Parallelogram Let’s lookat a parallelogram. What happens if we slice off the slanted parts on the ends? What will the area formula be now that it is a rectangle? bh
- 38. Parallelogram Be carefulthough! The height has to be perpendicular from the base, just like the side of a rectangle! bh
- 39. Parallelogram Be carefulthough! The height has to be perpendicular from the base, just like the side of a rectangle! bh
- 40. Parallelogram Be carefulthough! The height has to be perpendicular from the base, just like the side of a rectangle! bh
- 41. Rhombus The rhombusis just a parallelogram with all equal sides! So it also has bh for an area formula. bh
- 42. Practice! Parallelogram Rhombus3 in 9 in 4 cm 2.7 cm
- 43. Answers 10.8 cm2 27 in 2 Parallelogram Rhombus 3 in 9 in 4 cm 2.7 cm
- 44. Let’s try somethingnew with the parallelogram.
- 45. Let’s try somethingnew with the parallelogram. Earlier, you saw that you could use two trapezoids to make a parallelogram.
- 46. Let’s try somethingnew with the parallelogram. Earlier, you saw that you could use two trapezoids to make a parallelogram. Let’s try to figure out the formula since we now know the area formula for a parallelogram.
- 47.
- 48.
- 49. Trapezoid So wesee that we are dividing the parallelogram in half. What will that do to the formula?
- 50. Trapezoid So wesee that we are dividing the parallelogram in half. What will that do to the formula? bh
- 51. Trapezoid So wesee that we are dividing the parallelogram in half. What will that do to the formula? bh 2
- 52. Trapezoid But nowthere is a problem. What is wrong with the base? bh 2
- 53. Trapezoid b h2 So we need to account for the split base, by calling the top base, base 1 , and the bottom base, base 2 . By adding them together, we get the original base from the parallelogram. The heights are the same, so no problem there.
- 54. Trapezoid ( b1 + b2 ) h 2 So we need to account for the split base, by calling the top base, base 1 , and the bottom base, base 2 . By adding them together, we get the original base from the parallelogram. The heights are the same, so no problem there. base 2 base 1 base 1 base 2
- 55. Practice! Trapezoid 11m 3 m 5 m
- 56. Answers 35 m2 Trapezoid 11 m 3 m 5 m
- 57.
- 58.
- 59.
- 60. Summary so far...bh bh
- 61. Summary so far...bh bh 2
- 62. Summary so far...bh bh 2
- 63. Summary so far...bh bh 2
- 64. Summary so far...bh bh 2
- 65. Summary so far...bh bh 2
- 66. Summary so far...bh bh 2
- 67. Summary so far...bh bh 2
- 68. Summary so far...bh bh 2
- 69. Summary so far...bh bh 2
- 70. Summary so far...bh bh 2
- 71. Summary so far...bh bh 2 ( b1 + b2 ) h 2
- 72. Summary so far...bh bh 2 ( b1 + b2 ) h 2
- 73. Summary so far...bh bh 2 ( b1 + b2 ) h 2
- 74. Summary so far...bh bh 2 ( b1 + b2 ) h 2
- 75. Summary so far...bh bh 2 ( b1 + b2 ) h 2
- 76. Summary so far...bh bh 2 ( b1 + b2 ) h 2
- 77. So there isjust one more left!
- 78. So there isjust one more left! Let’s go back to the triangle. A few weeks ago you learned that by reflecting a triangle, you can make a kite.
- 79. Kite So thereis just one more left! Let’s go back to the triangle. A few weeks ago you learned that by reflecting a triangle, you can make a kite.
- 80. Kite Now wehave to determine the formula. What is the area of a triangle formula again?
- 81. Kite Now wehave to determine the formula. What is the area of a triangle formula again? b h 2
- 82. Kite Now wehave to determine the formula. What is the area of a triangle formula again? b h 2 Fill in the blank. A kite is made up of ____ triangles.
- 83. Kite Now wehave to determine the formula. What is the area of a triangle formula again? b h 2 Fill in the blank. A kite is made up of ____ triangles. So it seems we should multiply the formula by 2.
- 84. Kite b h2 *2 = b h
- 85. Kite Now wehave a different problem. What is the base and height of a kite? The green line is called the symmetry line, and the red line is half the other diagonal. b h 2 *2 = b h
- 86. Kite Let’s usekite vocabulary instead to create our formula. Symmetry Line* Half the Other Diagonal
- 87. Practice! Kite 2ft 10 ft
- 88. Answers 20 ft2 Kite 2 ft 10 ft
- 89.
- 90.
- 91.
- 92. Summary so far...bh bh
- 93. Summary so far...bh bh 2
- 94. Summary so far...bh bh 2
- 95. Summary so far...bh bh 2
- 96. Summary so far...bh bh 2
- 97. Summary so far...bh bh 2
- 98. Summary so far...bh bh 2
- 99. Summary so far...bh bh 2
- 100. Summary so far...bh bh 2
- 101. Summary so far...bh bh 2
- 102. Summary so far...bh bh 2
- 103. Summary so far...bh bh 2 ( b1 + b2 ) h 2
- 104. Summary so far...bh bh 2 ( b1 + b2 ) h 2
- 105. Summary so far...bh bh 2 ( b1 + b2 ) h 2
- 106. Summary so far...bh bh 2 ( b1 + b2 ) h 2
- 107. Summary so far...bh bh 2 ( b1 + b2 ) h 2
- 108. Summary so far...bh bh 2 ( b1 + b2 ) h 2
- 109. Summary so far...bh bh 2 ( b1 + b2 ) h 2
- 110. Summary so far...bh bh 2 ( b1 + b2 ) h 2
- 111. Summary so far...bh bh 2 ( b1 + b2 ) h 2
- 112. Summary so far...bh bh 2 ( b1 + b2 ) h 2 Symmetry Line * Half the Other Diagonal
- 113. Final Summary Makesure all your formulas are written down! b h b h 2 ( b1 + b2 ) h 2 Symmetry Line * Half the Other Diagonal