Types of triangles review

CCSS Math: 4.G.A.2
Review ways to classify triangles based on their sides lengths and angles.  Practice classifying triangles.

Classifying triangles by their angles

Acute triangles

An acute\blueD{\text{acute}} triangle has 3 angles that\blueD{\text{3 angles that}} each measure less than 90\blueD{\text{each measure less than } 90^\circ}. Below are examples of acute triangles\blueD{\text{acute triangles}}.

Right triangles

A right\purpleD{\text{right}} triangle has 1 angle that measures 90\purpleD{\text{1 angle that measures } 90^\circ} and 22 acute angles. Below are examples of right triangles\purpleD{\text{right triangles}}.

Obtuse triangles

An obtuse\greenD{\text{obtuse}} triangle has one angle that measures\greenD{\text{one angle that measures}} more than 90\greenD{\text{more than } 90^\circ} and 22 acute angles. Below are examples of obtuse triangles\greenD{\text{obtuse triangles}}.
Want to learn more about classifying triangles? Check out this video.
Problem 1A
Classify PQR\triangle{PQR} by its angles.
Choose 1 answer:
Choose 1 answer:

Want to try more problems like this? Check out this exercise

Classifying triangles by their side lengths

Equilateral triangles

An equilateral\blueD{\text{equilateral}} triangle has three equal sides\blueD{\text{three equal sides}}. Below are examples of equilateral\blueD{\text{equilateral}} triangles.

Isosceles triangles

An isosceles\purpleD{\text{isosceles}} triangle has at least\purpleD{\underline{\text{at least}}} two equal sides\purpleD{\text{two equal sides}}. Below are examples of isosceles\purpleD{\text{isosceles}} triangles.

Scalene triangles

A scalene\greenD{\text{scalene}} triangle has no equal sides\greenD{\text{no equal sides}}. Below are examples of scalene\greenD{\text{scalene}} triangles.
Problem 2A
Classify PQR\triangle{PQR} by its sides.
Choose all answers that apply:
Choose all answers that apply:

Want to try more problems like this? Check out this exercise.