Key Facts
- Hangul: 삼각형; Revised Romanization: samgakhyeong; pronounced [sam-ga-kyeong]
- Part of speech: noun
- Origin: Sino-Korean, hanja 三角形 (三 three + 角 corner + 形 shape)
- Register: neutral; school and shape vocabulary
Triangle in Korean: What Does 삼각형 Mean?
삼각형 is the school and maths word for a triangle: a figure with three sides and three corners. It is neutral. You use it for the shape in a drawing, a roof or a road sign, and it combines with other words, such as 직각삼각형, a right triangle.
Everyday speech has a native alternative, 세모, for any three-sided shape. The shorter root 삼각 turns up in compounds, for example 삼각김밥. Its four-sided counterpart is 사각형, so the shape words follow the number of corners.
How Do You Pronounce 삼각형?
The spelling is sam-gak-hyeong, but the spoken form is [sam-ga-kyeong]. When a ㄱ is followed by a ㅎ, the two sounds fuse into an aspirated k, so the final k of 각 moves across and joins the next syllable. Say sam, then ga, then kyeong with a puff of air, and do not say hyeong on its own. The romanization keeps the h because this is a noun.
Example Sentences with 삼각형
삼각형을 그려 보세요.
Samgakhyeongeul geuryeo boseyo.
Please draw a triangle.
그려 보세요 is please try drawing. The object particle 을 follows 삼각형, and in speech it sounds like [sam-ga-kyeong-eul].
이 지붕은 삼각형이에요.
I jibungeun samgakhyeongieyo.
This roof is triangular.
지붕 is a roof, and 삼각형이에요 uses the noun as a description, so the roof is triangular. The ending 이에요 is the copula.
삼각형에는 변이 세 개 있어요.
Samgakhyeongeneun byeoni se gae isseoyo.
A triangle has three sides.
변 is a side of the shape, and 세 개 is three items. The sentence states the basic fact that a triangle has three sides.
Common Phrases and Collocations
These collocations name the shape in drawings, outlines and kinds of triangle.
| Korean | Meaning |
|---|---|
| 삼각형을 그리다 | to draw a triangle |
| 삼각형 모양 | triangle shape |
| 직각삼각형 | right triangle |
The Mistake to Avoid
Learners read the third syllable as if the h were a separate sound.
Wrong: ✗ sam-gak-hyeong (each letter read separately)
Correct: ✓ sam-ga-kyeong
ㄱ followed by ㅎ blends into an aspirated k. Say the ㄱ with the next syllable, so the word has the rhythm sam, ga, kyeong.
삼각형 Compared with 세모, 삼각 and 사각형
Three shape words sit near 삼각형. The table shows how formal each one is.
| Word | Meaning | How it differs |
|---|---|---|
| 삼각형 | triangle | The standard shape word. |
| 삼각 | triangle (root) | Used in compounds, e.g. 삼각김밥. |
| 세모 | triangle (native) | Everyday word for a three-sided shape. |
| 사각형 | quadrilateral | Four-sided counterpart. |
Read the page for square to see the four-sided shape words.
Where Does the Word Come From?
삼각형 is Sino-Korean, written 三角形 in hanja: 三 (three) plus 角 (corner) plus 形 (shape). The word reads literally as three-corner shape, so the first syllable gives the number and the second the corner.
In Art Class: Choosing a Shape for a Roof
Two classmates are making a paper house. They use 삼각형 to discuss a shape and then name the object that will use it.
Jisu
이 종이로 삼각형을 만들까요?
I jongiro samgakhyeongeul mandeulkkayo?
Shall we make a triangle with this paper?
Alex
네, 지붕을 만들어요.
Ne, jibungeul mandeureoyo.
Yes, let’s make a roof.
Jisu
큰 삼각형이 필요해요?
Keun samgakhyeongi piryohaeyo?
Do we need a big triangle?
Alex
아니요, 작은 삼각형이면 돼요.
Aniyo, jageun samgakhyeongimyeon dwaeyo.
No, a small triangle will do.
종이로 means “with paper”, naming the material. 큰 and 작은 mean “big” and “small” before a noun. In the final line, 이면 돼요 means that something is enough or will do. The classmates are choosing the size of a cutout, rather than naming a special kind of triangle.
Where Will You Hear 삼각형 and 세모?
삼각형 is the precise shape name in a maths lesson, a geometry diagram or a description of a design. 세모 is also natural when talking about a simple outline, a button or a paper shape. Neither word is rude; the difference concerns the type of description, rather than politeness.
When referring to a screen control, 세모 모양 means “triangle-shaped”. The shape alone does not tell you what the control does. A triangle can be a play symbol in one interface and a different marker in another, so keep the shape description separate from the button's function.
Shape Words in Everyday Combinations
삼각형 모양 literally means “triangle shape” and is naturally translated as “triangular” or “triangle-shaped” before an object. It describes an outline. 삼각형을 그리다 means to draw a triangle, while 삼각형을 만들다 means to make one, for example from paper.
삼각김밥 uses the shorter 삼각 root to name triangular gimbap. The shape part comes before the food name. It is a compound name for a food, whereas 삼각형 can stand alone as the name of a geometric figure. You do not need to add 형 inside the established food name.
직각삼각형 is a right triangle: a triangle with a right angle. The longer name specifies a kind of triangle, rather than a larger or smaller triangle. Size words such as 큰 describe size; 직각 describes an angle property.
Words for Describing the Figure
| Korean | Meaning | Useful note |
|---|---|---|
| 변 | side | A straight edge of the triangle in a geometry discussion. |
| 각 | angle | Names an angle, rather than the length of a side. |
| 꼭짓점 | vertex | The point where two sides meet. |
| 도형 | geometric figure | A broader category that includes triangles and other shapes. |
The shapes vocabulary lesson teaches the wider set. When a task asks about 변, count or measure the sides; when it asks about 각, focus on the angles. The original sentence with 세 개 counts sides, so 변 is the word that makes the quantity meaningful.
Quick Self-Test
- Which root appears in the food name 삼각김밥?
- Does 큰 삼각형 mean a right triangle?
- Which word names a side: 변 or 각?
Show answers
- 삼각, without 형.
- No. It means a big triangle; 직각삼각형 is a right triangle.
- 변 means side; 각 means angle.
Frequently Asked Questions
How do you say triangle in Korean?
Say 삼각형 (samgakhyeong). Its spoken form is [sam-ga-kyeong].
Why is the h not heard in 삼각형?
The ㄱ and ㅎ blend into one aspirated k, so you hear kyeong. The noun's romanization keeps the h.
How do you say a right triangle?
Say 직각삼각형. It puts the right-angle word in front of 삼각형.
Is there a native Korean word for triangle?
Yes, 세모 is the everyday native word for a three-sided shape.
Related Words and What to Learn Next
- Theme list: shapes vocabulary sets 삼각형 beside circles, squares and stars.
- Index: Korean words A to Z.
- Practice: Add 삼각형 to your review in the vocabulary flashcard decks.
- Next in the list is the word for star shape.