This lesson focuses on the properties of triangles, a closed shape that has three sides, three vertices, and and three internal angles. There are different types of triangles such as a right triangle, obtuse, and acute based on the...

This lesson presents the idea that the area of any triangle is exactly half of a certain parallelogram -- thus we get the familiar formula of multiplying the base and the altitude and taking half of that. The lesson contains varied...

This task has students apply their knowledge of parallel lines to solve a geometric problem on areas of triangles. The task is open-ended in that students can choose their method of completing the task. Aligns with G-GPE.B.5.

How can trigonometry be used to find the area of a triangle or parallelogram? Does the triangle need to be a right triangle, and how accurate can the results possibly be? The answers to these questions are found here along with several...

This task is a relatively easy application of the formula for the area of a triangle and the use of parallel lines. Aligns with G-GPE.B.5.

This lesson presents the idea that the area of any right triangle is exactly half of a certain rectangle, and contains varied exercises for students.

In this lesson, learn all about the 30-60-90 triangle. Learn about its sides, its area, and the rules that apply to these triangles. Includes simulations and practice questions.

In this task, students must draw a diagram from a verbal description and use their understanding of similar triangles to find the area of a quadrilateral. Aligns with G-SRT.B.5.

Three circles are mutually tangent. Students are asked to find the total area of the circles plus the area inside where they meet. Students will need to know how to calculate the area of a circle, a sector of a circle, and an equilateral...

In this task, 8th graders are given the dimensions of two isosceles triangles and are asked to compare their areas. They must draw them and use the Pythagorean Theorem and the triangle area formula to solve the problem. Aligns with 8.G.B.7.

This tutorial provides a brief introduction about what area is, then gives the formulas for area of a square, rectangle, parallelogram, trapezoid, triangle, and circle. Examples of each formula are provided.

In Spanish. This interactive activity shows how to compute the area of a triangle and the concept of altitude, median and angle bisector. [Requires Java.]

An equilateral triangle is a special case of a triangle where all 3 sides have equal length and all 3 angles are equal to 60 degrees.

Thought provoking entry discusses the many outrageous ideas about the so-called mysterious disappearances of the Bermuda Triangle area in the Atlantic Ocean.

Jerry and Ashley are trying to find out if it is possible to see the lowest point in the USA from the highest point in the USA. It turns out that the highest point in the United States, the peak of Mount Whitney, is only 85 miles from...

This project resulted from of the collaboration of a computer aided drafting teacher, Chris Bond, and a math teacher, Lee Cable, (Hewitt-Trussville High School) to provide higher math expectations in CT and real life application in...