Curated OER
Isosceles Triangle Theorem
For this geometry worksheet, young scholars differentiate between isosceles and regular triangles. They calculate the area and perimeter of the triangle. There are eleven questions with an answer key.
Curated OER
Law of Sines
In this Law of Sines worksheet, learners describe, in their own words, when to use the law of sines. They give an example of a problem using the law of sines. This two-page worksheet contains one problem and a sample answer.
Curated OER
Value of Triangles
In this geometry activity, students identify the missing sides and angles of triangles. They find the midsegment of each triangle. There are nine questions with an answer key.
Curated OER
Special Right Triangles
Students identify the different parts of a right triangle. In this geometry lesson, students use the Pythagorean Theorem to identify missing sides and angles of a right triangle. They work with irrational and rational roots.
Inside Mathematics
Hopewell Geometry
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...
Inside Mathematics
Rhombuses
Just what does it take to show two rhombuses are similar? The assessment task asks pupils to develop an argument to show that given quadrilaterals are rhombuses. Class members also use their knowledge of similar triangles to show two...
Curated OER
Ratios in Right Triangles
Learners calculate the sides of right triangles in this trigonometric ratios lesson. They use Cabri Jr. software and TI-83 or TI-84 calculators to find the side lengths and their ratios to each other for various triangles. The provided...
Alabama Learning Exchange
Triangle Area: No Height? Use the Sine
No height? No problem! Learners use their knowledge and a little help from GeoGebra to develop the Law of Sines formula. The Law of Sines helps to determine the height of triangles to calculate the area.
Curated OER
Angle Bisectors
In this angle bisector worksheet, 10th graders solve and complete 23 various types of geometry problems. First, they find the angles listed in the figure shown. Then, students determine the sum of the interior angles of a polygon. They...
EngageNY
Checking for Identical Triangles II
Given a diagram of connected or overlapping triangles, individuals must find congruent parts using various properties. Pictures include reflexive sides and vertical angles amongst the marked congruent parts.
National Council of Teachers of Mathematics
Scale Factor
Does doubling mean everything doubles? Learners adjust the scale factor between two rectangles. Using the calculated measurements, pupils investigate the ratios between the lengths, perimeters, and areas of the rectangles.
101 Questions
Snail's Pace
Time doesn't fly when you're watching a snail cross a sidewalk. Combining the concepts of the Pythagorean Theorem and the distance, rate, and time formula, learners determine how long it takes a snail to go from one corner of a sidewalk...
Curated OER
The Law of Cosines
For this Law of Cosines worksheet, students are asked to demonstrate the ability to apply the Trigonometric Law of Cosines and the Inverse Law of Cosines to solve for sides and angles of right triangles.
Curated OER
Countdown Challenge: Triangle Inequality Theorem
For this triangle inequality worksheet, students test the Triangle Inequality Theorem. They measure the sides of given triangles, identify the type of triangle, and name angles in the triangle. The one-page worksheet contains 36 problems.
Curated OER
A Special Relationship
Students discover the relationships of the lengths of the sides of right triangles and right triangles using a series of drawings on dot paper. They investigate and solve problems of standard (customary and metric units) and non-standard...
Curated OER
Area and Perimeter
In this area and perimeter learning exercise, 10th graders solve and complete 18 various types of geometry problems. First, they find the area of a figure shown with consecutive sides perpendicular. Then, students find the area and...
Curated OER
Triangle Fundamentals Multiple Choice
In this triangles worksheet, students identify the parts of a triangle. They determine the value of an angle measurement, and identify the characteristics of triangles. This two-page worksheet contains 10 problems. This...
El Paso Community College
Geometry Definitions
Geometry is full of shapes, figures, and corresponding things here and there. The guide shares all of the key pieces of geometric information in a nicely color-coded and labeled sheet.
Alabama Learning Exchange
Triangle Congruence with Rigid Motion
Combine transformations and triangle congruence in a single activity. Scholars learn to view congruent triangles as a rigid transformation. Using triangle congruence criteria, learners identify congruent triangles and the rigid...
EngageNY
Congruence Criteria for Triangles—ASA and SSS
How do you know if a pair of triangles are congruent? Use the lesson to help class members become comfortable identifying the congruence criteria. They begin with an exploration of ASA and SSS criteria through transformations and...
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...
Centre for Innovation in Mamatics Teaching
Area, Perimeter and Volume
Develop young mathematicians' knowledge of two- and three-dimensional shapes with this geometry workbook. From learning about the classifications of different shapes and figures to calculating their area, perimeter, and volume, this...
Illustrative Mathematics
Are These Right?
Is that a right triangle or a wrong triangle? Young mathematicians look at eleven different shapes and use a measuring tool of their choice to determine which triangles have right angles. Consider cutting out sets of the shapes to...
CK-12 Foundation
Angle-Angle-Side Triangles: Garden Gate
Good fences make good gardens. Individuals use an interactive to see how angles and sides relate in a triangular-shaped garden fence. They apply the Law of Sines to find the length of the garden gate (third side of triangle) given two...