In this triangle similarity instructional activity, 10th graders solve and complete 12 different problems that include defining similar and 3 similar statements using only sides and angles. First, they determine if each pair of triangles...

Students prove and apply theorems of triangle inequality and hinge theorem. In this geometry lesson, students will discuss which triangle is bigger and why. They will use theorems, such as Exterior Angle Inequality or the Pythagorean...

In this understanding triangles learning exercise, students read 6 pages of examples and explanations about identifying triangles, determining length of sides and degrees of angles, including the hypotenuse, then answer 28 questions,...

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,...

Students identify and use the similarity theorem. In this geometry lesson, students differentiate between congruent and similar triangles. They solve problems using the computer modifying shapes by dragging.

Learners classify triangles and make connections regarding angle measurements and attributes of acute, right, and obtuse triangles. They listen to teacher define and explain triangles. Everyone imagines a place where a broken wing for a...

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...

In this geometry worksheet, 10th graders complete an indirect proof and order the sides or angles of a triangle. Also, students determine if a triangle can have sides with the given lengths. The two page worksheet contains twelve...

What does it mean for a quadrilateral to be cyclic? Mathematicians first learn what it means for a quadrilateral to be cyclic. They then investigate angle measures and area in such a quadrilateral.

Students identify missing sides and angles. In this geometry lesson, students use triangular theorems to identify the missing sides. They use the Pythagorean Theorem to find the different ratios of each side.

In this triangles worksheet, students solve 40 problems in which Pythagoras' theorem is used to check if a triangle is right-angled. This page is intended for online use but may be completed on paper.

In this triangle inequality theorem worksheet, students determine the lengths of the sides of triangles and identify the measure of angles. This one-page worksheet contains ten triangle theorem problems.

Seventh graders relate the Pythagorean theorem to the real world. For this algebra lesson, 7th graders identify important properties of the Pythagorean theorem and use it to solve word problems. They create a step by step plan to...

In this geometry activity, 10th graders write two-column and paragraph proofs to prove angle pair relationships.  The one page activity contains five problems.  Answers are not included. 

Students play a game to reinforce concepts of the Pythagorean Theorem. In this geometry lesson plan, students find the missing angle and lengths of a right triangle. They use properties of trigonometry about sine, cosine and tangent to...

Students identify interior and exterior angles of polygons. In this geometry lesson, students add interior and exterior angles of polygons. They use angle theorems to solve the problems.

Students discover that side measurement is used in determining angle classification of a triangle. By squaring sides, they predict whether triangles be right, obtuse, or acute. They prove the Pythagorean Theorem and use it to solve...

High schoolers investigate the relationship between angle measures and sides of a triangle and the relationships among the three sides of a triangle. The use of technology (Cabri, Jr.) allows learners to make and test conjectures as they...

In this triangles worksheet, students identify the median, altitude, segment, angle bisector, perpendicular bisector and triangle midsegment of triangles.  They find the perimeter of triangles.  This three-page worksheet...

Students draw triangles and explore the classification of each using the measures of interior angles and lengths of sides. They investigate the sum of the interior angles of various triangles and conjecture and prove the theorem: The...

For this geometry worksheet, students solve word problems by finding the values of missing angles and missing sides of triangles. They review their trigonometric properties of a right triangle. There are 9 problems with an answer key.

What figure is formed by connecting the midpoints of the sides of a quadrilateral? The geometry assessment task has class members work through the process of determining the figure inscribed in a quadrilateral. Pupils use geometric...

Students engage in a study of the Pythagorean Theorem to classify the hypotenuse of a triangle. The teacher uses examples from the lesson to aid students in comprehension of solving problems that involve problem solving. They create a...

Circles are the foundation of many geometric concepts and extensions - a point that is thoroughly driven home in this extensive unit. Fundamental properties of circles are investigated (including sector area, angle measure, and...