Curated OER
Angles in a Triangle
In this geometry instructional activity, 10th graders determine the measure or measures of the missing angle(s) in a triangle. The one page interactive instructional activity contains four questions. Answers and hints are included.
Curated OER
Triangle Sum Theorem
Teach your class how to solve problems using the triangle sum theorem. In this geometry lesson, students identify the missing angles in a triangle using the sum theorem. They graph triangles on the TI and moves the sides around to create...
EngageNY
The Angle-Angle (AA) Criterion for Two Triangles to Be Similar
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...
Curated OER
Find The Missing Angle of Triangles
In this triangle worksheet, students find the missing angle in a set of 4 triangles. Answers are included on page 2. A reference web site is given for additional activities.
Mathed Up!
Angles: Parallel Lines
Viewers are presented with seven problems with parallel lines and angle relationships and must use the given information to find the measures of specific angles. To finish, they explain their process in finding the measures in the...
Curated OER
Geometry Worksheet- Angle
In this geometry worksheet, students solve questions dealing with angles, triangles, and quadrilaterals. They calculate the missing angle. There are 2 questions.
Curated OER
Triangles
In this triangles worksheet, learners solve for the missing angles and missing sides on the triangles given. Students complete 12 problems total.
Curated OER
Special Triangles and Quadrilaterals
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...
EngageNY
Law of Sines
Prove the Law of Sines two ways. The ninth segment in a series of 16 introduces the Law of Sines to help the class find lengths of sides in oblique triangles. Pupils develop a proof of the Law of Sines by drawing an altitude and a second...
EngageNY
Similarity and the Angle Bisector Theorem
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...
EngageNY
More About Similar Triangles
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...
EngageNY
Special Relationships Within Right Triangles—Dividing into Two Similar Sub-Triangles
Why are right triangles so special? Pupils begin their study of right triangles by examining similar right triangles. Verifying through proofs, scholars recognize the three similar right triangles formed by drawing the altitude. Once...
Curated OER
Determine the Measure of an Angle of a Right Triangle.
In 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.
Curated OER
Applying Special Right Triangles
In this geometry worksheet, 10th graders use the theorems regarding right triangles to find the missing length in a special right triangle. The one page worksheet contains eleven questions. Answers are included.
Curated OER
Right Triangle Trigonometry
In this geometry worksheet, 10th graders use right triangle trigonometry to find the missing angle measure. The two page worksheet contains fourteen problems. Answers are provided.
Curated OER
Mixed Right Triangles
In this geometry learning exercise, 10th graders use right triangle trigonometry to find the missing angle measure or side length in right triangles. The one page interactive learning exercise contains ten questions. Answers and hints...
EngageNY
The Definition of Sine, Cosine, and Tangent
Introduce your classes to a new world of mathematics. Pupils learn to call trigonometric ratios by their given names: sine, cosine, and tangent. They find ratios and use known ratios to discover missing sides of similar...
Curated OER
Inverse Functions in Trigonometry
In this inverse functions in trigonometry worksheet, students find the missing angles in eight right triangles, given the length of two sides.
Curated OER
Trigonometric Triangles
In this trigonometry worksheet, students find the missing angle and sides given the 6 trigonometric values. There are 6 questions with an answer key.
Curated OER
Using Algebraic Equations in Geometry Problems
In this using algebraic equations in geometry problems worksheet, 6th graders write an equation to solve each addition problem about geometry, then find the solution.
Mathematics Assessment Project
Hopewell Geometry
Right triangles from 2,000 years ago? Learners investigate different right triangles found in the earthworks of the Hopewell people, a Native American culture that populated the United States from 200BC to AD 500. Learners apply concepts...
Curated OER
Missing Angle Problems
In this problem solving worksheet, 6th graders focus on the angles described in each word problem. Students must solve for each of the 6 problems, giving a written explanation for each in the space provided.
Curated OER
Special Segments in a Triangle
In this geometry worksheet, 10th graders review the vocabulary associated with the special segments of a triangle and the associated points of concurrency and solve problems in which they find the indicated missing angle or...
Curated OER
Area Measures and Right Triangles
Your class will investigate the relationship among different triangles. This geometry lesson, demonstrates how to make a connection between triangles and the Pythagorean Theorem. They identify the missing side or angle of a triangle.