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Types of triangles review
Review ways to classify triangles based on their sides lengths and angles. Practice classifying triangles.
Classifying triangles by their angles
Acute triangles
An triangle has . Below are examples of .
Right triangles
A triangle has and acute angles. Below are examples of .
Obtuse triangles
An triangle has and acute angles. Below are examples of .
Want to learn more about classifying triangles? Check out this video.
Want to try more problems like this? Check out this exercise
Classifying triangles by their side lengths
Equilateral triangles
An triangle has . Below are examples of triangles.
Isosceles triangles
An triangle has . Below are examples of triangles.
Scalene triangles
A triangle has . Below are examples of triangles.
Want to try more problems like this? Check out this exercise.
Want to join the conversation?
- Why can't I go back to selecting? I got a wrong and I can't go back(77 votes)
- It just won't let you.(24 votes)
- why is the isosceles triangle and the equilateral both classified as each other(48 votes)
- because an equilateral triangle is all equill sides and an isosceles triangle is two or more equill sides(19 votes)
- Is their any more triangle practices?(23 votes)
- No. You will have to do them over if you want extra practice.(12 votes)
- Why are triangles used in math?(16 votes)
- it is because it uses geometry(9 votes)
- I don’t understand why an equilateral triangle is constantly being defined as and Isosceles triangle.(8 votes)
- An equilateral triangle has 3 equal length sides. An isosceles triangle has at least 2 sides of the same length. Thus all equilateral triangles are also isosceles.(30 votes)
- if all of the angels are acute but lenghths are different what is that?(6 votes)
- i got my one right but it said i got it worng(12 votes)
- I... I think that means you got it wrong, but you don't understand. You might want to check your answer or ask someone else to explain it to you.(4 votes)
- um whenever i double tap a question it ameatiatily says its wrong(10 votes)
- dont double tap just tap and check(6 votes)
- it said that a acute was like all the sides lower then 90* but the last one was over 90*(7 votes)
- then it was obtuse(4 votes)
- Why do all sides measurements in a triangle have to equal 180(3 votes)
- Nice question! I think you meant to ask why all the angle measurements in a triangle add to 180 degrees. The side measurements can add up to anything.
There is a geometry proof of the fact that the angles in a triangle must add to 180 degrees.
Draw a triangle with vertices at points A, B, and C, and draw a line through vertex C that is parallel to side AB. This diagram forms three non-overlapping angles at vertex C. Two of the angles are just outside the triangle and one of the angles is angle C inside the triangle.
These three non-overlapping angles formed at vertex C clearly add to 180 degrees (because together, they form a semicircle).
Because alternate interior angles are congruent when parallel lines are cut by another line (transversal), angle A in the triangle is congruent to one of the angles at C outside the triangle, and angle B in the triangle is congruent to the other angle at C outside the triangle.
It follows from these last two statements that angles A, B, and C in the triangle add to 180 degrees.
Have a blessed, wonderful day!(11 votes)