This lesson focuses on the properties of triangles, a closed shape that has three sides, three vertices, and and three internal angles. There are different types of triangles such as a right triangle, obtuse, and acute based on the...

This lesson explores the equation of the median of a triangle formula, sum of medians of a triangle, altitude of a triangle, median of equilateral triangle formula, and median of a triangle definition while discovering the interesting...

Explore the world of the altitude of a triangle in this mini-lesson including its definition, altitudes in different types of triangles, formulae, some solved examples, and a few interactive questions for you to test your understanding.

This lesson explores triangle inequality theorem, triangle inequality theorem-proof, and triangle inequality theorem problems. Try the hands-on triangle inequality theorem calculator and interactive problems to have a better...

In this lesson, learn all about the 30-60-90 triangle. Learn about its sides, its area, and the rules that apply to these triangles. Includes simulations and practice questions.

Student will use primary and secondary sources to gain a richer understanding of women's activism and how the Triangle Shirtwaist Fire led to changes in labor and safety regulations in America.

[Free Registration/Login may be required to access all resource tools.] Different types of right triangles and trigonometric ratios for special right triangles are covered in this study guide.

Understand the mathematical meaning of a triangle and the idea of congruence, or sameness, in geometry.

MathWorld goes into detail about equilateral triangles at this site. Use this site to find out how to construct an equilateral triangle using a compass and straight edge. Learn about the altitude of such triangles, and the rationality of...

This task provides a good opportunity to use isosceles triangles and their properties to show an interesting and important result about triangles inscribed in a circle with one side of the triangle a diameter. The fact that these...

In each of the following diagrams, two triangles are shaded. Based on the information given about each diagram, decide whether there is enough information to prove that the two triangles are congruent. Aligns with G-CO.B.

The goal of this task is to use similarity transformations to relate two triangles. The triangles are obtained by taking midpoints of two sides of a given triangle. Aligns with HSG-CO.C.10.

The goal of this task is to understand how congruence of triangles, defined in terms of rigid motions, relates to the corresponding sides and angles of triangles. Aligns with G-CO.B.7.

In this task, learners must prove that angles and triangles are congruent and that a parallel line passes through the midpoints of two sides of the larger triangle. Aligns with G-SRT.B.4.

Given distinct, congruent triangles, students are asked to show that congruence can always be shown with one, two, or three rigid motions. Aligns with G-CO.A.5.

The goal of this task is to examine similarity of triangles from the point of view of proportional sides, showing that this is sufficient to conclude that two triangles are similar. Aligns with HSG-SRT.A.2.

Using known facts about the unit circle and isosceles triangles together with the Pythagorean Theorem, young scholars can derive the sine and cosine of special angles. Aligns with HSF-TF.A.3.

Using known facts about the unit circle and isosceles triangles together with the Pythagorean Theorem, young scholars can derive the sine and cosine of special angles. Aligns with HSF-TF.A.3.

This activity will help learners visualize the construction of congruent triangles and conceptualize properties through measurement and movement of their construction. Students will need access to the TI-84 Plus Family.

Students will use their TI-84 Plus and Cabri Jr to investigate SSS triangle congruence.

Use the triangle congruence criteria SSS, SAS, ASA, and AAS to determine that two triangles are congruent.

In this task, 8th graders explore congruence and transformations of two triangles on a coordinate grid. Aligns with 8.G.A.2.

This task shows the congruence of two triangles formed by cutting a rectangle in half along the diagonal. Students are asked to investigate elements of congruence and transformations among the shapes. Aligns with 8.G.A.2.

In this activity, the student can visually identify number patterns in Pascal's triangle by coloring multiples of a given number.