Triangles and Trigonometry
Introduction
Properties of Triangles
Midsegments and Similarity
Triangle Congruence
Pythagoras’ Theorem
Isosceles and Equilateral Triangles
Trigonometry
Sine and Cosine Rules

Share

Reset Progress

This will delete your progress and chat data for all chapters in this course, and cannot be undone!

Glossary

Select one of the keywords on the left…

Triangles and TrigonometryIsosceles and Equilateral Triangles

Reading time: ~5 min

Other then right-angled triangles, there are a few other triangles with special properties. In this section we’ll have a look at some of them.

Isosceles Triangles

We say that a triangle is isosceles if it has two congruent sides. These congruent sides are called the legs of the triangle, while the third side is called the base.

COMING SOON – Base angles theorem Proof by constructing angle bisector and using SAS result.

COMING SOON – Find the height of an Isosceles Triangles using Pythagoras

Equilateral Triangles

We say that a triangle is equilateral if all of its sides have the same length. You’ve already seen how to construct an equilateral triangle using straight-edge and compass.

COMING SOON – Size of angles in an equilateral triangle

COMING SOON – Area of an equilateral triangle