Equilateral and Isosceles Triangles

Examples, solutions, videos, games, activities and worksheets to help SAT students review properties of equilateral and isosceles triangles.

The following diagram shows the Isosceles Triangle Theorem. Scroll down the page for more examples and solutions.

 

Equilateral Triangles
A brief look at equilateral triangles and their properties.

Isosceles Triangles
Brief look at isosceles triangles and the Isosceles Triangle Theorem.
Isosceles triangles have at least two congruent sides and at least two congruent angles. The congruent sides, called legs, form the vertex angle. The other two congruent angles are the base angles. Isosceles triangles are used in the regular polygon area formula and isosceles right triangles are known as 45-45-90 triangles.

Try the free Mathway calculator and problem solver below to practice various math topics. Try the given examples, or type in your own problem and check your answer with the step-by-step explanations.

We welcome your feedback, comments and questions about this site or page. Please submit your feedback or enquiries via our Feedback page.