Math Planet
Math Planet: Pre Algebra: Measure Areas
Demonstrates how to calculate the area of two-dimensional shapes using formulas. Covers parallelogram, triangle, trapezoid, and circle. Includes a video modeling how to find the area of a circle and a triangle. [0:59]
Texas Education Agency
Texas Gateway: Solving Quadratic Equations Using Algebraic Methods
Given a quadratic equation, the student will solve the equation by factoring, completing the square, or by using the quadratic formula.
Paul Dawkins
Paul's Online Notes: Algebra: Quadratic Equations Part Ii
Detailed math tutorial features notes and examples that illustrate how to solve quadratic equations using complete the square then use that to derive the quadratic formula.
Mathigon
Mathigon: Algebra: Arithmetic and Geometric Sequences
This lesson focuses on arithmetic and geometric sequences using several examples and practice exercises.
Mathigon
Mathigon: Algebra: Fibonacci Numbers
This lesson focuses on Fibonacci numbers, a pattern based on the sum of the two previous numbers. It offers examples and practice exercises using some form of Fibonacci numbers.
Math Is Fun
Math Is Fun: Area of Triangles Without Right Angles
Learn how to find the area of triangles without right angles. Find the formula to use depending on the information you know about the triangle: base and height, three sides, or two sides and an angle.
Purple Math
Purplemath: Solving Polynomials: How To
Demonstrates the steps involved in solving a general polynomial, including how to use the Rational Roots Test and synthetic division. Points out when using a graphing calculator can be very helpful.
Purple Math
Purplemath: Special Factoring: Differences of Squares
Demonstrates how to use the formula for finding the differences of squares, and warns against trying to factor a sum of squares.