Classroom Tools Series: Mathematics
Online lessons for Geometry, Trigonometry, Statistics, and Probability
Geometry
Here’s a simple list of formulas which can be very helpful in solving geometric problems. Please note that r denotes radius, h altitude, l slant height, b base, B area of base, Ө central angle expressed in radians.
Shape | Formula |
Triangle | Area = ½bh |
Rectangle | Area = bh
Diagonal = √(b2 h2) |
Trapezoid | Area = ½h (b1 b2) |
Circle | Arc = r Ө
Circumference = 2πr
Area = πr2 |
Circular Sector | Area = ½r2 Ө |
Rectangular
Parallelepiped | If a, b, c are the sides,
Volume = abc
Diagonal = √(a2 b2 c2) |
Prism | Volume = Bh |
Pyramid | Volume = ⅓Bh |
Right Circular
Cylinder | Lateral surface = 2 πrh
Volume = πr2h |
Right Circular
Cone | Lateral surface = πrl
Volume = ⅓πr2h |
Sphere | Surface = 4πr2
Volume = 4/3 πr3 |
For more lessons, worksheets, and lesson plans, check out the links below!
Geometry Lesson Plans by Teach-nology
Geometry Worksheets by Fun Maths
Interactive Pythagorean Theorem by MathsNet (needs Java-enabled browser)
Interactive Activities for Geometry by Interactivate (needs Java-enabled browser)
More online Geometry Resources by HomeSchool Math (some resources with applets and puzzles)
Trigonometric Functions
Determining the solutions of a right triangle involves the application of trigonometric functions or the ratios of the sides of any right triangle. Solving a right triangle can help answer actual problems like in physics, measurements, surveying, and navigation.
Considering the triangle on the right, the basic trigonometric functions of the acute angle A are given below. Remember: SOH-CAH-TOA!
For more lessons, worksheets, and lesson plans, check out the links below!
Lessons on Trigonometric Functions of Any Angle by The Math Page
Lessons on Trigonometry by Syvum
Lessons on Trigonometry and Right Triangles by Zona Land
Trigonometric Table Cheat Sheet by SOS Math
Table on Trigonometric Identities by SOS Math
Study table for the Six Trigonometric Functions by Study Stack
More online Trigonometry Resources by HomeSchool Math (some resources with applets and puzzles)
Statistics and Probability
How can you present numerical data and interpret them? How can you predict the risk or failure of a situation? Statistics and probability can be your best tools in analyzing and drawing conclusions from gathered data.
For more lessons, worksheets, and lesson plans, check out the links below!
Lessons on Statistics by Math Forum
Sample quizzes and exercises by Math Forum
Interactive activities for Statistics by Interactivate (needs Java-enabled browser)
Interactive activities for Probability by Interactivate (needs Java-enabled browser)
More online Statistics and Probability Resources by HomeSchool Math
Sources:
Adanza, E., et. al. “Plane Trigonometry”. Manila: Rex Printing Co., Inc., 1998
n.d. “Trigonometric Functions”. Wikipedia. Retrieved on October 15, 2007 from http://en.wikipedia.org/wiki/Trigonometric_function
(Published 22 October 2007, Smart Schools Program)
