Khan Academy: Area of a Triangle on a Grid

This lecture explores the area of each triangle created by drawing two diagonal lines through a rectangle. It provides a detailed explanation of how to use a formula to solve the given problem. Tip: Use this for test preparation purposes.

This video is the first installment in a series devoted to exploring Heron's Formula. It is a high-level experience that delves into proof using algebra. It demonstrates a step-by-step process for finding the area of a triangle using...

Learn to break up oddly shaped quadrilaterals into shapes where finding the area is more easily determined.

While the lesson focuses on right triangles, this activity offers a great way to practice the area of all triangles through an interactive webpage. The activity begins with the class taking a square paper and cutting in in half; can they...

Sal finds a shaded area defined by two equilateral triangles whose side lengths are given.

It's always nice to have a plan B. Pupils investigate an alternate formula for the area of a triangle that uses sine. A set of challenge questions shows how the new formula relates to the well-known formula of (1/2)bh.

A video that demonstrates how to solve equations with variables on both sides. The first two examples give the equation and the third example is a word problem in which an equation must be written and then solved. This video is also...

Demonstrates solutions to problems #17-20 of California Geometry released state test questions. Problems address understanding of similar triangles, parallelograms and properties of the diagonals of parallelograms. [11:11]

In this video tutorial [7:28], the instructor shows how to determine if two triangles are congruent using different triangle congruence postulates: SSS, SAS, ASA, AAS. Practice problems available.

Explains how to solve a given word problem that involves similar triangles. The problem requires that two unknown side lengths be determined. [5:34]