Solid Figures 7 th Grade Georgia Standard of Excellence: MGSE7.G.6 Solve real-world and mathematical problems involving area, volume and surface area of two- and three- dimensional objects composed of triangles, quadrilaterals, polygons, cubes, and right prisms. Gail Sherman 2013
A right prism is a geometric solid that has a polygon as its base and vertical sides perpendicular to the base. The base and top surface are the same shape and size. It is called a “right” prism because the angles between the base and sides are right angles. What is a Right Prism?
Volume GMAS Formula Sheet gives the following formula for the volume of right prisms: V = (Area of base) x (Height) Area of the base is just lw or length x width The height is how tall it is. Huh? What? Pardon Me?
Volume of a Rectangular Prism (Review from 6 th grade) What is the shape of the base? rectangle Find area of the base. 3x10 = 30 What is the height? 5 Final Answer? 3x10x5 = 150 units³
Your Turn Find area of the base. What is the height? Final Answer? 4 in. 5 in. 9 in. 4 x 5 = 20 9 (l x w) x h= (4x5) x 9 = 180in
Volume of a Triangular Prism What is the shape of the BIG B base? triangle Find the area of base. (5x10)/2 = 25 What is the height? 4 Final Answer? 4(5x10)/2 = 100 units³
Nets Draw a net of a cube. How many faces? 6
Surface Area of a Cube Let’s name the faces of our cube. Front Back Top Bottom Left Right If each side is 3 inches long, find the surface area.
Add the areas of the 6 faces! Front is…… 3x3=9 Back is……. 3x3=9 Top is……… 3x3=9 Bottom is… 3x3=9 Left is……… 3x3=9 Right is……. 3x3=9 And the TOTAL is 54 in²
Rectangular Prism Just a box. Draw a net for this rectangular prism
How does your net compare? ☺ It’s ok to be different! ☺ Now find the surface area
.. Surface Area of a Rectangular Prism Front = Back = Top = Bottom = Right = Left = Total = 4 2 7
Rectangular Prism Front = 4x7=28 Back = 4x7=28 Top = 2x7=14 Bottom = 2x7=14 Right = 2x4=8 Left = 2x4=8 Total = 100 units ² 4 2 7
Nets Draw a net of a triangular prism. How many faces? 4in. 5 in. 2 in.
Parts of the Triangular Prism Triangle Rectangle 4in. 5 in. 2 in.
Add the Parts of the Triangular Prism Triangle Rectangle Total = 4in. 5 in. 2 in. ½bh= ½(5x4) =10 lw=5x2 = in
Pyramid Net Draw a net for the square pyramid 5 ft 6 ft
Use the net to name the parts of the pyramid. Square Triangle 5 ft 6 ft
Write Formulas & Compute Square Triangle lw = ½ bh= 5x5 = ½ (5x6)= ft