# Acute and obtuse triangles

An acute triangle (or acute-angled triangle) is a triangle with three acute angles (less than 90°). An obtuse triangle (or obtuse-angled triangle) is a triangle with one obtuse angle (greater than 90°) and two acute angles. Since a triangle's angles must sum to 180° in Euclidean geometry, no Euclidean triangle can have more than one obtuse angle. Acute and obtuse triangles are the two different types of oblique triangles — triangles that are not right triangles because they do not have a 90° angle. (Wikipedia).

What is an obtuse triangle

👉 Learn the essential definitions of triangles. A triangle is a polygon with three sides. Triangles are classified on the basis of their angles or on the basis of their side lengths. The classification of triangles on the bases of their angles are: acute, right and obtuse triangles. The cl

From playlist Types of Triangles and Their Properties

What is an acute triangle

👉 Learn the essential definitions of triangles. A triangle is a polygon with three sides. Triangles are classified on the basis of their angles or on the basis of their side lengths. The classification of triangles on the bases of their angles are: acute, right and obtuse triangles. The cl

From playlist Types of Triangles and Their Properties

What is an equilateral triangle

👉 Learn the essential definitions of triangles. A triangle is a polygon with three sides. Triangles are classified on the basis of their angles or on the basis of their side lengths. The classification of triangles on the bases of their angles are: acute, right and obtuse triangles. The cl

From playlist Types of Triangles and Their Properties

How to label a triangle as acute obtuse, right or equiangular

👉 Learn how to classify triangles. A triangle is a polygon with three sides. Triangles are classified on the basis of its angles or on the basis of its side lengths. The classification of triangles on the bases of its angles are: acute, right and obtuse triangles. The classification of tri

From playlist Classify Triangles

What is an equiangular triangle

👉 Learn the essential definitions of triangles. A triangle is a polygon with three sides. Triangles are classified on the basis of their angles or on the basis of their side lengths. The classification of triangles on the bases of their angles are: acute, right and obtuse triangles. The cl

From playlist Types of Triangles and Their Properties

What is a right triangle

👉 Learn the essential definitions of triangles. A triangle is a polygon with three sides. Triangles are classified on the basis of their angles or on the basis of their side lengths. The classification of triangles on the bases of their angles are: acute, right and obtuse triangles. The cl

From playlist Types of Triangles and Their Properties

What is an isosceles triangle

👉 Learn the essential definitions of triangles. A triangle is a polygon with three sides. Triangles are classified on the basis of their angles or on the basis of their side lengths. The classification of triangles on the bases of their angles are: acute, right and obtuse triangles. The cl

From playlist Types of Triangles and Their Properties

Animation: Types of Angles

Illustrated acute, right, obtuse, straight, reflex, and full angles http://mathispower4u.wordpress.com/

From playlist Angles and Right Triangles

Determine if a triangle is acute or obtuse using the Pythagorean inequality theorem

👉 Learn how to classify triangles. A triangle is a polygon with three sides. Triangles are classified on the basis of its angles or on the basis of its side lengths. The classification of triangles on the bases of its angles are: acute, right and obtuse triangles. The classification of tri

From playlist Classify Triangles

EngageNY Grade 4 Module 4 Lesson 13

EngageNY/Eureka Math Grade 4 Module 4 Lesson 13 For more videos, please visit http://bit.ly/engageportal PLEASE leave a message if a video has a technical difficulty (audio separating from the video). Occasionally, Explain Everything will do that, requiring me to re-render the video. Scr

From playlist EngageNY Grade 4 Module 4

Applying the pythagorean inequality theorem to classify triangles as acute right or obtus

Learn about the Pythagorean theorem. The Pythagoras theorem is a fundamental relation among the three sides of a right triangle. It is used to determine the missing length of a right triangle. The Pythagoras theorem states that the square of the hypotenuse (the side opposite the right angl

From playlist Geometry - PYTHAGOREAN THEOREM

Incenter, Circumcenter, Orthocenter & Centroid of a Triangle - Geometry

This geometry video tutorial explains how to identify the location of the incenter, circumcenter, orthocenter and centroid of a triangle. The incenter can be found be drawing the 3 angle bisectors of a triangle and identifying the point of intersection. The incenter always lie inside of

From playlist Geometry Video Playlist

Law of Cosines calculator SSS

I make short, to-the-point online math tutorials. I struggled with math growing up and have been able to use those experiences to help students improve in math through practical applications and tips. If I helped you in this video, I would love to have you subscribe. My subscribers are my

From playlist Law of Cosines

How to classify polygons by the measure of their angles

👉 Learn all about classifying triangles. A triangle is a closed figure with three sides. A triangle can be classified based on the length of the sides or based on the measure of the angles. To classify a triangle based on the length of the sides, we have: equilateral (3 sides are equal), i

From playlist Triangles

How does the pythagorean inequality theorem prove obtuse triangles

Learn about the Pythagorean theorem. The Pythagoras theorem is a fundamental relation among the three sides of a right triangle. It is used to determine the missing length of a right triangle. The Pythagoras theorem states that the square of the hypotenuse (the side opposite the right angl

From playlist Geometry - PYTHAGOREAN THEOREM

Is a Triangle Right, Acute, or Obtuse Given Sides? (Pythagorean Converse)

How to tell whether a triangle is acute, right, obtuse, or not even a triangle at all. We discuss a number of examples in this free math video tutorial by Mario's Math Tutoring. 0:11 How to Know if a Triangle is Right, Acute or Obtuse Formula 1:00 Example 1 Given 5, 12, 14 Right, Acute or

From playlist Geometry

The Law of Sines: The Ambiguous Case

This video explains how to solve a triangle using the law of sines when given SSA. Search all videos at http://mathispower4u.wordpress.com/

The Pythagorean Theorem and The Converse of the Pythagorean Theorem

This video shows how to use the Pythagorean Theorem and its Converse to determine if a triangle is acute, right, or obtuse. http://mathispower4u.yolasite.com/

From playlist Angles and Right Triangles

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