1 / 28

Grade 8 Surface Area #2

Grade 8 Surface Area #2. Surface area. The surface area of a solid figure is the sum of the areas of all faces of the figure.

carlota-ramos
Télécharger la présentation

Grade 8 Surface Area #2

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. Grade 8 Surface Area #2 CONFIDENTIAL

  2. Surface area The surface area of a solid figure is the sum of the areas of all faces of the figure. An area of study closely related to solid geometry is nets of a solid. Imagine making cuts along some edges of a solid and opening it up to form a plane figure. The plane figure is called the net of the solid. The surface area of a rectangular solid is expressed in square units.

  3. In general, Surface Area of solid figures = 2 x area of the base +perimeter of the base x height If, B = area of the base P = perimeter of the base h = height SA = Surface Area Then, SA = 2B +Ph

  4. s s s s s s s s s Cubes A cube is a three-dimensional figure with all edges of the same length. If s is the length of one of its sides, then SA = 2(s2) + (4s)s = 6s2

  5. h w l h w l Rectangular prism SA = 2B + Ph SA = 2(lw) + (2l + 2w)h = 2(lw + lh + wh)

  6. Let us do some practice problems!

  7. 1) The perimeter of one face of a cube is 48 cm. What is its surface area? • 862cm2 • 864cm2 • 866cm2 • 868cm2 CONFIDENTIAL 7

  8. A B C 3ft 2ft 2ft 6ft 1ft 3ft 2ft 3ft 4ft 2) Which of the given boxes has thegreatest surface area? • Box A • Box B • Box C • All have equal surface area 8 CONFIDENTIAL

  9. 3) The bottom of a closed rectangular box has an area of 50 square centimeters. If the box is 8 centimeters high and the length is twice the width, what is the surface area of the box? • 320 cm2 • 330 cm2 • 340 cm2 • 350 cm2 9 CONFIDENTIAL

  10. 4) Each small cube in the rectangular prism below has edges of length 2 centimeters. What is the surface area of the prism in square centimeters? • 220 cm2 • 222 cm2 • 224 cm2 • 208 cm2 10 CONFIDENTIAL

  11. 5) What is the surface area of the box with the given dimensions? • 1134 cm2 • 1224 cm2 • 1194 cm2 • 1154 cm2 CONFIDENTIAL 11

  12. 30 cm 20 cm 40 cm 6) How much wrapping paper will be needed to cover the gift box shown below without any overlapping? • 5000 cm2 • 5100 cm2 • 5200 cm2 • 5300 cm2 12 CONFIDENTIAL

  13. 4 5 B 3 A C 4 2 1 7 6 4 7) Which of the following statement about the boxes is true? • Surface area of A > Surface area of B • Surface area of A = Surface area of B • Surface area of A = Surface area of C • Surface area of C < Surface area of B 13 CONFIDENTIAL

  14. 8) What is the surface area of a cube, if the area of each face of the cube is 16 ft2? • 64 ft2 • 96 ft2 • 128 ft2 • 256 ft2 14 CONFIDENTIAL

  15. 9) What isthesurface area of the given box? • 136 in2 • 124 in2 • 132 in2 • 142in2 15 CONFIDENTIAL

  16. 1ft 1ft 1ft 10) If the length of each side of the cube is doubled, how does it affect the surface area? • The surface area is increased by 2 times. • The surface area is increased by 4 times. • The surface area is increased by 6 times. • The surface area is increased by 9 times. 16 CONFIDENTIAL

  17. Assessment

  18. 1) What is the surface area of a rectangularpacking box 11 in. long, 5 in. wide, and 4 in. high. • 200 in2 • 210 in2 • 238 in2 • 230 in2 CONFIDENTIAL 18

  19. 2) What is the surface area of the given rectangular prism. • 1800 cm2 • 1900 cm2 • 2000 cm2 • 2100 cm2 19 CONFIDENTIAL

  20. 3) What total number of unit cubes would be needed to fill the given box? • 105 • 125 • 100 • 150 20 CONFIDENTIAL

  21. 1ft 1ft 1ft 4) If the given cube is cut into two equal parts, then what will be the change in total surface area? • The total surface area will decrease by 2 times. • The total surface area will decrease by 1.5 times. • The total surface area will increase by 2 times. • The total surface area will increase by 1.3 times. 21 CONFIDENTIAL

  22. 5) The perimeter of one face of a cube is 36 cm. What is its surface area? • 486cm2 • 364cm2 • 566cm2 • 268cm2 22 CONFIDENTIAL

  23. 6) What is the surface area of the given prism? • 420.5 in2 • 320.5 in2 • 430.5 in2 • 630.5 in2 23 CONFIDENTIAL

  24. 6 6 B 4 A C 6 3 2 8 7 6 7) Which of the following statement about the boxes is false? • Surface area of A > Surface area of B • Surface area of B > Surface area of C • Surface area of A > Surface area of C • Surface area of A < Surface area of B 24 CONFIDENTIAL

  25. 1ft 1ft 1ft 8) If the length of each side of the cube is tripled, how does it affect the surface area? • The surface area is increased by 2 times. • The surface area is increased by 4 times. • The surface area is increased by 6 times. • The surface area is increased by 9 times. 25 CONFIDENTIAL

  26. 25 cm 15 cm 45 cm 9) How much wrapping paper will be needed to cover the gift box shown below without any overlapping? • 4375 cm2 • 4275 cm2 • 4350 cm2 • 4075 cm2 26 CONFIDENTIAL

  27. 10) What is the surface area of the given cube? • 35.5 cm2 • 36.5 cm2 • 37.5 cm2 • 38.5cm2 27 CONFIDENTIAL

  28. You did a great job today!

More Related