Can you name the types of triangles?

This type of triangle has...	Type of Triangle
three congruent sides
at least two congruent sides
no congruent sides
three congruent angles
three angles less than 90 degrees
one angle greater than 90 degrees
one angle equal to 90 degrees
a number of aircraft and surface vessels disappear

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Types of Triangles Quiz

Rating:	Report a mistake
Created by: varivas -
Published: April 8th, 2009
Category: Science
Plays: 155,001

Tags: Math Quizzes, geometry, type, triangle

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	JoeGrzzly:	Apr 8th, 2009 at 18:57 GMT	56 points
	Couldn't spell isosceles for the life of me.

	mattrd08:	Apr 8th, 2009 at 19:04 GMT	10 points
	I had to spellcheck isosceles as well.

	Gravey:	Apr 8th, 2009 at 19:06 GMT	133 points
	There's nothing quite as fun as inventing a word like 'equiangular' and having it be right.

	SowCrates:	Apr 8th, 2009 at 19:07 GMT	11 points
	just goes to show that wrong pronunciation can help you learn how to spell, at the cost of looking like an idiot in public when you talk.

	chikinmunkee:	Apr 8th, 2009 at 19:08 GMT	74 points
	It's funny that I have a degree in mathematics and yet I've never heard of an equiangular triangle.

	David:	Apr 8th, 2009 at 19:08 GMT	127 points
	equiangular triangles are equilateral triangles.

	[Deleted]:	Apr 8th, 2009 at 19:09 GMT	88 points
	Yeah, if the three sides are the same length, don't the angles all have to be the same as well?

	Big_B:	Apr 8th, 2009 at 19:10 GMT	72 points
	Agreed, if the three sides are the same, then the three angles are the same. If the three angles are the same, then the three sides have to be the same. I have never heard of an equiangular triangle.

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	mjenks:	Apr 8th, 2009 at 19:15 GMT	0 points
	e·qui·an·gu·lar adj. Having all angles equal. Looks like it's a word to me.

	peanut4:	Apr 8th, 2009 at 19:16 GMT	30 points
	If a triangle has three equal sides it has three equal angles, and vice versa. So equiangular and equilateral are the same thing. I've got a maths degree and had never heard the former term.

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	MissInformed:	Apr 8th, 2009 at 19:23 GMT	54 points
	What, no "bermuda" as a bonus answer? Chalk me up as another who'd never heard of "equiangular" before.

	Jack:	Apr 8th, 2009 at 19:23 GMT	23 points
	Jesus, Is this place just a train stop for losers with math degrees? On that note, I am going to have to throw myself in the mix of a loser with a math degree who has never heard of, and was annoyed by, the "equiangular' triangle.

	Kicking222:	Apr 8th, 2009 at 19:36 GMT	19 points
	"Equiangular", as many have said above, is bull. I'm with Jack- loser, math degree, unknown, annoyed.

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	eln77:	Apr 8th, 2009 at 19:40 GMT	6 points
	@GRAVEY Yah I totally guessed at that one too, I was amazed it was correct. This quiz gave me horrible flashbacks to high school geometry. Sporcle, you'll be receiving my therapy bill in the mail.

	benjamin stewart:	Apr 8th, 2009 at 19:40 GMT	17 points
	Being one with a math degree, and I teach geometry, we can name triangles by either their sides OR their angles. Yes, an angle that is equilateral is also equiangular. The quiz was asking for the different ways we can describe triangles, by either their sides or their angles. For fun, it would have been nice to see a degenerate triangle (a triangle with 2 zero degree angles).

	montecarlo:	Apr 8th, 2009 at 19:50 GMT	8 points
	sorry, not a math geek, just a physics geek (weak, i know). what if the triangle is on a non-2d surface? then can it be equiangular, yet not equilateral? sorry, its been awhile since i was in advanced calc.

	benjamin stewart:	Apr 8th, 2009 at 19:55 GMT	0 points
	a triangle is a polygon which are all 2 dimensional "shapes." The do not have to be solely on a plane, a flat surface. They can exist on on surfaces of 3 dimensional objects.

	RobH:	Apr 8th, 2009 at 19:56 GMT	4 points
	@benjamin. I assume that looks just like a straight line with the final angle as 180 degress. Still, kind of cool that that exists and has a name. :)

	ted:	Apr 8th, 2009 at 19:58 GMT	5 points
	I like 'equiangular.' I'd never heard of it, but as gravey said above, it was fun making it up. But I can't believe I forgot scalene--man was I kicking myself trying to recall that one.

	mjenks:	Apr 8th, 2009 at 20:03 GMT	7 points
	@ benjamin stewart: aren't the three verteces of a triangle on the same plane, by definition of a plane (three non-linear points contains one and only one plane)?

	sevorak:	Apr 8th, 2009 at 20:06 GMT	19 points
	An equilateral triangle only has to be equiangular in Euclidean geometry. In certain non Euclidean systems this isn't true.

	thevictor390:	Apr 8th, 2009 at 20:28 GMT	8 points
	^ This is exactly what I was about to say. Consider a spherical geometry. You can then have a triangle with three right angles. That said, I think Euclidean geometry is a safe assumption. And equiangular exists, just refers to the angles rather than sides. Yes they are the same thing, but so is a line and a degenerate triangle, as someone pointed out.

	jzev:	Apr 8th, 2009 at 21:20 GMT	1 point
	No Bermuda Triangle?

	millandas:	Apr 8th, 2009 at 21:22 GMT	3 points
	Maybe types of quadrilaterals next?

	LoveShack:	Apr 8th, 2009 at 22:03 GMT	2 points
	not many more people got scalene than those that got equiangular. i think people have been peeking at the comments. equiangular though, never heard of it... i would say that's the same as equilateral

	davidr:	Apr 8th, 2009 at 22:12 GMT	3 points
	@RobH: `Degenerate' is used for any object in mathematics that fits the definition but in a `stupid' way like that. So a point is also a degenerate triangle (three sides of zero length) and a degenerate circle (zero radius), a degenerate sphere (ditto) and a degenerate almost everything else.

	davidr:	Apr 8th, 2009 at 22:16 GMT	4 points
	@MattJ: Yes, you can always draw a plane through the three vertices of a triangle. However, a triangle is a two-dimensional shape that can be defined on any surface. For example, you can define a triangle on the surface of the Earth with one vertex at the north pole and two on the equator, 90° longitude apart. There is a plane through the vertices but that's not the surface on which the triangle exists. (It is, by the way, an equilateral triangle with three 90° angles. Well, it is if you assume the Earth is a sphere.)

	DWolf:	Apr 8th, 2009 at 22:22 GMT	4 points
	I accept equiangular as valid, as the people talking about the ways of describing triangles pointed out, even if (at least in a plane) all equilateral triangles are equiangular and vice versa. With that, I will have to say I also had to guess what the name would be since I don't remember ever hearing it before. "Equilateral is equal sides, so equal angles should be equi...angular? Wow, that was right!?!"

	danzam:	Apr 8th, 2009 at 22:31 GMT	6 points
	when in doubt, think of The Simpsons. Homer Simpson fished a pair of glasses out of the toilet and said "The sum of the square root of two sides of a isosceles triangle is equal to the square root of the remaining side!" A person sitting in the toilet in another stall yelled "THAT'S A RIGHT TRIANGLE, YOU IDIOT!"

	zalagreensbury:	Apr 8th, 2009 at 22:37 GMT	-1 points
	Woah, what's the big deal I missed one. Sporcle is coldblooded today,lol.

	DoubleUnderscore:	Apr 8th, 2009 at 22:39 GMT	1 point
	Same as most other people here, I had no idea about the 4th one, so just made up a few words, tried them and got it after a couple.

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	BJack:	Apr 8th, 2009 at 23:29 GMT	2 points
	@Andy B: a triangle is defined by three points, which davidr described. It's still a triangle, albeit a more exotic one than most people will ever consciously deal with. :)