3. Surface Area What does it mean to you? Does it have anything to do with what is in the inside of the prism.? Surface area is found the 7 th grade way by finding the area of all the sides and then adding those answers up. How will the answer be labeled? The area on the outside of the shape Nope, the inside is volume The 8 th grade way uses a formula Units 2 because it is area!

4. 7 th Grade Rectangular Prism How many faces are on here? 6 Find the area of each of the faces. A B C 4 5 in 6 Do any of the faces have the same area? A = 5 x 4 = 20 x 2 =40 B = 6 x 5 = 30 x 2 = 60 C = 4 x 6 = 24 x 2 = 48 If so, which ones? 148 in 2 Opposite faces are the same. Find the SA

5. 8 th grade SA You can find the SA of any prism by using the basic formula for SA which is Ph + 2B= SA P= perimeter of the base h= height(distance between the bases) B = the base of the prism.

6. 8 th grade Rectangular Prism Total SA= Ph+2B Find the perimeter (P) and area the base(B). A B C 4 5 in 6 SA=Ph+2B SA=20 x 5 + 2x 24 SA=100 + 48 SA=48 in 2 P= 4+6+4+6 = 20 B = 4 x 6 = 24 h= 5

7. 7 th Grade Cube Are all the faces the same?YES 4m How many faces are there? 6 Find the Surface area of one of the faces. A 4 x 4 = 16Take that times the number of faces. X 6 96 m 2 SA for a cube.

8. 8 th Grade Cube SA = Ph+2B 4m SA = 16x4 + 2x16 P=4+4+4+4= 16 h=4 B=4x4 A SA = 64 + 32 96 m 2 SA for a cube.

9. 7 th Grade Triangular Prism How many faces are there? 5 How many of each shape does it take to make this prism? 2 triangles and 3 rectangles = SA of a triangular prism 4 3 5 10 m Find the surface area. Start by finding the area of the triangle. 4 x 3/2 = 6 How many triangles were there? 2 x 2 = 12 Find the area of the 3 rectangles. 5 x 10 = 50 = front 4 x 10 = 40 = back 3 x 10 = 30 = bottom SA = 132 m 2 What is the final SA?

10. 8 th Grade Triangular Prisms Use the same triangular prism we used before. Let’s use the formula this time. Ph + 2B= SA BE CAREFUL! Triangular prisms have a base of a triangle even if it’s laying on the rectangle. Find the perimeter of that same base and multiply it by the height of the prism. Find the area of the base, which is a triangle because it is a triangular prism. You will need two of them. Add those two things. Now you should have the same answer as before. Either way is the correct way.

11. 8 th Grade Triangular Prism P=4+3+5=12 h=10 B= ½ 3x4=6 SA = Ph+2B 4 3 5 10 m SA = 12x10+2x6 SA = 120+12 SA = 132 m 2

12. Cylinders 6 10m Only 8 th grade 2 B 3.14 x 9 = 28.26 X 2 = 56.52 Ph (circumference x height) 3.14 x 6 =18.84 x 10 = 188.4 Total SA = 244.92 Ph+2B = SA This time P=circumference of the base Since you were given the diameter choose the C=πd formula

13.  Why should you learn about surface area?  Is it something that you will ever use in everyday life?  If so, who do you know that uses it?  Have you ever had to use it outside of math?