Skip to main content
Create interactive lessons using any digital content including wikis with our free sister product
. Get it on the
Pages and Files
Complementary and Supplementary Angles
Congruent Similar Angles
Constructing Angles of a Given Size
Drawing a Net for Rectangular Prisms and Square Pyramids
How To Draw A Net For A Cylinder & Triangle
measuring angles with a protractor
Types of Angles
Types of Triangels by Angels
Types of Triangles by Angle
Vertically Opposite Angles
Vertices and Edges of 3D Shapes
Add "All Pages"
An Unknown Angle Of A Triangle.
What is an angle?
An angle is two rays that share the same endpoint to form an angle. The point where the two rays intersect is called the vertex of the angle. The two rays are called the sides of the angle.
What is a triangle?
Triangles are one of the fundamental figures used in Euclidean geometry.
There are three elements required to make a triangle. It is a..
• plane or two-dimensional figure
• the sum of the interior angles equal exactly 180º
There are two common systems of a triangle classification. One of the focuses on the
sides and designates three types of triangles.
Equilateral means "equal sides," and in an equilateral triangle, all three sides are the same length. This means that the angles will also be equal - all 60° - making the triangle equiangular as well.
An isosceles triangle has two congruent sides called legs and a third side called the base. The vertex angle is the angle is included by the legs. The other two angles are called the base angles. The base angles are congruent. The figure below depicts an isosceles triangle with all the parts labeled.
Scalene comes from a word meaning "uneven," and a scalene triangle has three unequal sides. As you might suspect, then, the three angles are unequal as well.
In an acute triangle, the largest internal angle is acute – less than 90°. This means that all the angles are acute.
In a right triangle, there is one right angle – an angle of exactly 90°. This means that the other two angles will be acute.
How to find the missing angle
of an unknown angle of a triangle..
help on how to format text
Turn off "Getting Started"