Math Concepts in Three-Dimensional Figures Explained
Learn about volume, area, perimeter, circumference, and surface area of various shapes including cubes, prisms, cylinders, pyramids, cones, spheres, and circles. Understand formulas through word problems.
Math Concepts in Three-Dimensional Figures Explained
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Presentation Transcript
By Angelica Gonzalez 2nd Period 8th Grade Math Chart
Volume • The amount of space, measured in cubic units, that an object takes up. • Prism: V=Bh • Cylinder: V=Bh • Pyramid: V=1/3Bh • Cone: V=1/3Bh • Sphere: V=4/3(3.14)r^3
Word Problem • A cylinder has a diameter of 14 inches and a height of 21 inches. What is its volume? A=3.14(7^2) A=3.14(49) A=153.86 V=153.86(21) 14 in. 21 in. V = 3,231.06 in. V=Bh A=3.14(r^2)
Pi • The ratio of the circumference to the diameter of a circle; equal to about 3.141592+.
Area • The area of a figure is the number of squares required to cover it completely. • Square: A=s^2 • Rectangle: A=lw or A=bh • Triangle: A=1/2bh or A=bh/2 • Circle: A=(3.14)r^2
Word Problem • A circle has a radius of 5 cm. Find the area. A = 3.14 (r^2) A=3.14(5)^2 A=3.14(25) 5 cm. A = 78.5 cm.
Perimeter • A path that surrounds an area. • Square: P=4s • Rectangle: P=2l+2w or P=2(l+w)
Word Problem • What is the perimeter of this figure? P = 2(l + w) P = 2 (9 +4) P = 2 (13) P = 26 in. 4 in. 9 in.
Circumference • The size of something as given by the distance around it. • Circle: C=2(3.14)r
Word Problem • If a circle has a diameter of 8 inches, what is the circumference? 8 in. 3.14 * 8 = 25.12 in.
Surface Area • A measure of the number of square units needed to cover the faces or surfaces of a figure. • Cube(total): S=6s^2 • Prism(lateral): S=Ph • Prism(total): S=Ph+2B • Pyramid(lateral): S=1/2Pl • Pyramid(total): S=1/2Pl+B • Cylinder(lateral): S=2(3.14)rh • Cylinder(total): S=2(3.14)rh+2(3.14)r^2 or S=2(3.14)r(h+r)
Word Problem • Find the lateral surface area a cylinder with a height of 12 cm. and a diameter of 8 cm. 8 cm. S = 2(3.14)rh S = 6.28 (4) h S = 25.12 (12) 12 cm. S = 301.44 cm.
Pythagorean Theorem • a^2+b^2=c^2
Simple Interest Formula • I = prt
P • P represents the perimeter of the base of a three-dimensional figure.
B • B represents the area f the base of a three-dimensional figure.