Math Planet
Math Planet: Geometry: More About Triangles
Explores triangles and related vocabulary through examples and a video lesson.
Math Planet
Math Planet: Geometry: Triangles: Inequalities
Gain an understanding of how to list the sides of a triangle in order from shortest to longest by viewing examples and a video lesson. [1:01]
McGraw Hill
Glencoe Mathematics: Online Study Tools: Triangles and Angles
This site gives a short interactive quiz which allows students to self-assess their understanding of the concept of triangles and angles.
McGraw Hill
Glencoe Mathematics: Online Study Tools: Self Check Quiz on Triangles
Students show comprehension of Geometry skills. The online quiz assesses scholars on relationships in triangles.
Sophia Learning
Sophia: Triangle Exterior Angles Practice: Lesson 5
This lesson provides practice problems that apply the triangle exterior angles theorem. It is 5 of 6 in the series titled "Triangle Exterior Angles Practice."
University of Cambridge
University of Cambridge: Maths and Sports: Stadium Sightline
How would you design the seating for an Olympic stadium to give spectators the best view of events? This geometry and modelling activity is designed to be accessible to both GCSE and A-level maths students (Key Stage 4 and Key Stage 5),...
Illustrative Mathematics
Illustrative Mathematics: 6.g Same Base and Height, Variation 1
Make the following triangles on a geoboard. Remember that the pegs are equally spaced in a square grid. Compare the areas of the triangles. Aligns with 6.G.A.1.
Illustrative Mathematics
Illustrative Mathematics: 6.g Base and Height
The purpose of this task is to help young scholars understand what is meant by a base and its corresponding height in a triangle and to be able to correctly identify all three base-height pairs. Aligns with 6.G.A.1.
Illustrative Mathematics
Illustrative Mathematics: 6.g Same Base and Height, Variation 2
This is the second version of a task asking students to find the areas of triangles that have the same base and height. This presentation is more abstract as students are not using physical models. They still determine the area of each...
Illustrative Mathematics
Illustrative Mathematics: 6.g Polygons in the Coordinate Plane
The purpose of this task is for learners to practice plotting points in the coordinate plane and finding the areas of polygons. This task assumes that students already understand how to find areas of polygons by decomposing them into...
Mangahigh
Mangahigh: Shape: The Angles Inside a Triangle
Test your knowledge of the missing angle measure.
Mangahigh
Mangahigh: Shape: Types of Triangle
Test your knowledge of triangles by identifying the different types.
Mangahigh
Mangahigh: Shape: Proof of the Sum of the Angles in a Triangle
Determine that all angles in a triangle equal 180 degrees.
Mangahigh
Mangahigh: Shape: Proof of the Exterior Angle Theorem for a Triangle
Use your knowledge of exterior angles of a triangle to prove the theorem.
CK-12 Foundation
Ck 12: Geometry: Unknown Dimensions of Triangles Grade 6
[Free Registration/Login may be required to access all resource tools.] Find the unknown dimensions of a triangle given its area and another dimension.
CK-12 Foundation
Ck 12: Geometry: Unknown Dimensions of Triangles Grade 7
[Free Registration/Login may be required to access all resource tools.] Find unknown dimensions of triangles given area and one other dimension.
CK-12 Foundation
Ck 12: Trigonometry: Identify Accurate Drawings of Triangles
[Free Registration/Login may be required to access all resource tools.] Determine if diagrams of triangles are accurately drawn.
CK-12 Foundation
Ck 12: Geometry: Hl Triangle Congruence
[Free Registration/Login may be required to access all resource tools.] In this lesson students prove two right triangles are congruent with the Hypotenuse-Leg shortcut. Students examine guided notes, review guided practice, watch...
CK-12 Foundation
Ck 12: Geometry: Third Angle Theorem Grades 8 10
[Free Registration/Login may be required to access all resource tools.] Apply the Third Angle Theorem.
CK-12 Foundation
Ck 12: Elem Math: Classify Triangles, Composite Figures Number of Equal Sides
[Free Registration/Login may be required to access all resource tools.] Students watch a video overview and attempt practice problems on classifying a triangle inside a composite figure.
CK-12 Foundation
Ck 12: Elem Math: Classifying Right Obtuse or Acute by Angle Measure
[Free Registration/Login may be required to access all resource tools.] Students watch a video and attempt practice problems on how to classify triangles based on angle measures.
CK-12 Foundation
Ck 12: Elem Math: Counting the Number of Basic 2 D Shapes in a Set of Figures
[Free Registration/Login may be required to access all resource tools.] Students watch a video and attempt practice problems on identifying various 2D shapes in a set of figures.
Math Is Fun
Math Is Fun: Trigonometric Identities
A good introduction to trigonometric identities, equations that are always true for a right triangle and require knowledge of the functions sine, cosine, and tangent.