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...

Provide your emerging mathematicians with the tools to learn as they incorporate auxiliary lines to solve unknown angle proofs in this continuing segment. They decipher information from a diagram to uncover the missing pieces and...

We know theorems about circles—now what? Class members prove a theorem, with half the class taking the case where a point is inside the circle and half the class taking the case where a point is outside the circle. The lesson then...

In this trigonometric ratios instructional activity, students find the missing angle of 20 triangles by using sine, cosine and tangent ratios. Students compute the angle measurement of given ratios for six problems.

In this geometry activity, 10th graders use right triangle trigonometry to solve application problems in which they find the measure of the missing angle in a right triangle.  The two page activity contains five free response...

Touch a circle once. Individuals watch a video and learn two theorems related to tangents and circles. The pupils then apply the theorems to find missing angle measures and lengths in figures. At the end, they practice their skills on...

After reviewing characteristics of seven types of triangles, young geometers discover how to find the missing angle of a triangle. Then, they practice identifying triangles, find missing angles, and find missing side lengths of...

In this right triangles worksheet, students use trigonometric ratios to determine the length of a side of a triangle or a missing angle measurement.  This two-page worksheet contains 20 problems.

In this geometry worksheet, 10th graders use right triangle trigonometry to find the missing angle measure or side length.  The three page worksheet contains a combination of twelve multiple choice and free response problems. ...

In this geometry worksheet, learners find the missing angle that is inscribed inside of a circle. They define vocabularies related to the circle. There are 17 questions.

How do you solve an equation like trigonometry? Learners apply their understanding of trigonometric ratios to find unknown angles in right triangles. They learn the meaning of arcsine, arccosine, and arctangent. Problems include...

Math whizzes work with angle sums and exterior angles to figure out the measure of other angles. This particular publication provides comprehensive support in the form of an anticipatory activity, questions designed to prompt discussion,...

In this geometry activity, 10th graders use right triangle trigonometry to find the missing angle measure or side length in right triangles. The one page interactive activity contains ten questions. Answers and hints are included. 

In this right triangle trigonometry worksheet, students find the measure of specified angles. Students determine the length of the missing side of a right triangle. This four-page worksheet contains 24 problems. Answers to the worksheet...

High schoolers use similar triangles to find missing heights.  In this using similar triangles to find missing heights lesson, students use proportions to find the heights of missing side lengths.  High schoolers find the...

In this classifying angles worksheet, 10th graders solve and complete 21 various types of problems. First, they use the diagram shown on the right to answer the questions that follow. Then, students solve for x and find the measure of...

In this quadrilateral worksheet, students determine the measures of angles and their side lengths of a rectangle. There are 15 questions with multiple parts.

Students identify angles.  In this angles that pair lesson, students identify adjacent, vertical, complementary, and supplementary angles.  They use straws, pretzel sticks to demonstrate given types of angles. 

In this geometry worksheet, 10th graders identify complimentary and supplementary angles. They solve for missing angles and relate it to the right angle theorem. There are 16 questions with an answer key.

Students measure angles using a protractor. In this geometry lesson, students solve for the missing angles using equations set to the theorem of triangles. They measure missing angles through construction and identify congruent angles.

In this special triangles worksheet, students examine given special triangles.  They determine the length of a missing side and/or the measurement of a missing angle for given triangles and quadrilaterals.  Students justify...

Determine whether two triangles are similar. The lesson presents opportunities for pupils to find the criterion needed to show that two triangles are similar. Scholars use the definition of similarity to find any missing side...

In this geometry worksheet, students observe a triangle marked with three angles and are given two measures to find the missing third measure. A second diagram is given with six angles. There are 20 questions.

In the second of two similar worksheets, anglers compute missing angles when given an alternate, supplementary, or complementary value. There are six problems to solve, but each of them requires two to four solutions. This is a nice...