Need an activity for teaching the Pythagorean Theorem? Geometry juniors apply the Pythagorean theorem to two triangles to determine a final calculation. 

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...

How can congruent triangles help mark a soccer field? This is just one question your classes can answer after solving the real-world problems in the lesson. Each example posed through a word problem elicits higher-order thinking and...

Get lost in the classifications. Using the backdrop of the Bermuda Triangle, pupils classify it by angle and side measures. They also learn information about the triangle and its history.

Sixth graders investigate triangles and the inequality theorem. They will collaborate in groups to determine the length of a longest side of a triangle. Then relate the size of the triangle to its angles using protractors, yard sticks,...

Given a pair of parallel lines and a triangle in between, geometers prove that the sum of the interior angles is 180 degrees. This quick quest can be used as a pop quiz or exit ticket for your geometry class.

The problem seems simple: find the area of the equilateral triangle whose sides are each length 1. In fact, this same problem is solved in 8th grade, addressing a different Common Core standard, using the formula for area of a triangle...

What do you need to prove triangles are similar? Learners answer this question through a construction exploration. Once they establish the criteria, they use the congruence and proportionality properties of similar objects to find...

Incorporate geometry into the solving linear equations lesson. Pupils use their knowledge of geometry to write linear equations which reinforces geometry measurement concepts while at the same time providing a familiar context for...

Use a triangle area formula that works when the height is unknown. The eighth installment in a 16-part series on trigonometry revisits the trigonometric triangle area formula that previously was shown to work with the acute triangles....

How can shapes help solve literal equations? Scholars first learn to replace variables with shapes to aid in solving literal equations. A worksheet of practice problems helps hone the skill.

Fifth graders use a software program to practice their problem solving skills. As a class, they identify patterns in their days at school and review problem solving patterns in math. They solve different problems and discover that the...

Students draw a chart (included in the lesson) to use with their investigation. They review terminology of triangles and receive toothpicks to use in the lesson. Beginning with three toothpicks, students form a triangle. They complete...

Your visual geometry learners will appreciate triangle drawings as they model the triangle sum theorem and algebraically solve to find the missing interior angle in a triangle. Practice problems increase in complexity and vary in their...

In this congruent triangles worksheet, high schoolers solve four multiple choice problems. Students determine which statement is the appropriate reasoning to say that two triangles are congruent.

Right triangles are so special! Use special right triangles to discover the trigonometric ratios. Pairs construct special right triangles and find the values of the ratios of the sides. In the process, they discover the ratios stay the...

You literally need to use the resource. Young mathematicians solve geometric problems by using literal equations. They go on to solve distance/rate/time problems by using literal equations — a great progression that helps introduce the...

Scholars first investigate relationships in the side lengths of 30°-60°-90° triangles and 45°-45°-90° triangles. This knowledge then helps them solve problems later in the lesson about special right triangles.

Long considered the symbol of safe harbor and steadfast waiting, the lighthouse gets a mathematical treatment. The straightforward question of distance to the horizon is carefully presented, followed by a look into the...

Students explore their new classroom with this hunting and matching game. In this early childhood problem solving lesson, students use observation and matching skills as they hunt for pre-cut shapes around the classroom.

Concepts are only valuable if they are applicable. An informative resource uses concepts developed in lessons 26 and 27 in a 36-part series. Scholars write equations and solve for missing side lengths for given right triangles....

Students estimate and measure triangles. In this geometry lesson, students identify the relationship between three sides and a triangle. They use the inequality theorem to decide if a triangle will be formed or not.

Students discover that the sum of the lengths of any two sides of a triangle must be greater than the third side. They are shown how a triangle is formed using three strips such as that the triangle is seen inside the strips.

Young geometers become pool sharks in this analysis of the angles and lengths of a trick shot. By using angles of incidence and reflection to develop similar triangles, learners plan the exact placement of balls to make the shot....