Build confidence in proofs by proving a known property. Pupils explore two approaches to proving base angles of isosceles triangles are congruent: transformations and SAS. They then apply their understanding of the proof to more complex...

Identifying and verifying reproducible patterns in mathematics is an essential skill. Mathematicians identify the relationship of sides when an angle is bisected in a triangle. Once the pupils determine the relationship, they prove it to...

An informative lesson contains a brief explanation of how the sum of the angles of a triangle is a line. The lesson continues with determining the missing angle in a triangle, or solving for a variable. Using the sum of the...

Under which conditions can a triangle be classified as isosceles? High schoolers practice identifying isosceles triangles and special line segments, including angle bisectors, medians of triangles, and perpendicular bisectors of sides of...

In this trapezoids learning exercise, 10th graders solve 5 different problems related to trapezoids and applying the appropriate theorem. First, they define a trapezoid, including its bases, legs, and base angles. Then, students use the...

In this isosceles triangle worksheet, students solve 19 multiple choice and short answer problems.  Students use the isosceles triangle theorem to determine unknown angle measures.

In this geometry worksheet, students differentiate between isosceles and regular triangles. They calculate the area and perimeter of the triangle. There are eleven questions with an answer key.

In this Pythagorean theorem worksheet, 9th graders solve and complete 6 various types of problems. First, they find the length of a right-angled triangle's hypotenuse. Then, students determine which triangle is described and explain...

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...

The Hopewell people of the central Ohio Valley used right triangles in the construction of earthworks. Pupils use the Pythagorean Theorem to determine missing dimensions of right triangles used by the Hopewell people. The assessment task...

Your geometry learners use their knowledge of various geometric concepts to write proofs. Starting with givens containing parallel line segments with transversals and triangles and quadrilaterals, and the mid-point and distance formulas;...

For this geometry worksheet, 10th graders solve application word problems involving the use or right triangle trigonometry, including angle of elevation or depression. The one page interactive worksheet contains five questions. Hints,...

Looking to challenge your students that have mastered basic triangle congruence proofs? A collection of proofs employ previously learned definitions, theorems, and properties. Pupils draw on their past experiences with proofs to...

Enjoy this nicely organized worksheet that puts together multiple problems regarding trapezoid proofs. The resource can be used as a guide that begins with proving properties and ends with solving for measures of line segments.

Students investigate the Pythagorean Theorem. In this geometry lesson plan, students define angles and sides of right triangles. They calculate the area and surface area using formulas derived by the Pythagorean Theorem.

Challenge the class with inscribed circles in triangles. The assessment task requests class members use their knowledge of circles and right triangles to prove two triangles are congruent. They go on to utilize their knowledge of...

Stuck trying to remember the formal language of a geometric proof? Never fear, this handout has them all ready to go. The reasons are sectioned by topic so this handy guide is ready when you are to tackle those two column proofs. 

Students explore the concept of polygon properties. In this polygon properties lesson, students draw polygons with different numbers of sides such as pentagons, octagons, hexagons, etc. Students identify different geometric shapes in the...

[Free Registration/Login may be required to access all resource tools.] Apply the properties of isosceles triangles.

Explains the basic concept of isosceles triangles with step-by-step instructions and methods for solving specific problems on your own relating to this topic.