Translation guide
A triangle is a shape with three sides. In Japanese, the basic word is 三角形 (さんかくけい), but in everyday conversation, 三角 (さんかく) is more common. There are also specific terms for different types of triangles and related concepts.
Referring to the shape with three straight sides and three angles.
The most common, everyday word for 'triangle'. Used in casual conversation, for shapes, and in compounds like 三角定規 (triangle ruler).
This shape is a triangle.
The symbol △ is read as さんかく and is used in writing, such as in marking tests or indicating a triangle shape.
Describing specific kinds of triangles based on sides or angles.
Referring to things that are triangular in shape, like a musical instrument or a road sign.
A relationship involving three people, often romantic.
三角 (さんかく) is the everyday word for a triangle shape, while 三角形 (さんかくけい) is the formal geometric term. Use 三角 for casual descriptions and 三角形 in math class or technical writing.
There is a triangular origami on the desk.
Please fold it into a triangle.
The formal, mathematical term for 'triangle'. Used in geometry, textbooks, and technical contexts.
The sum of the interior angles of a triangle is 180 degrees.
Mark correct answers with a circle and incorrect ones with a triangle.
Equilateral triangle. All sides and angles are equal.
One side of the equilateral triangle is 5 cm long.
Isosceles triangle. Two sides are equal.
The base angles of an isosceles triangle are equal.
Right triangle. Has one 90-degree angle.
Calculate the hypotenuse of the right triangle.
Obtuse triangle. Has one angle greater than 90 degrees.
An obtuse triangle has one angle greater than 90 degrees.
Acute triangle. All angles are less than 90 degrees.
An acute triangle has all angles less than 90 degrees.
The musical instrument (triangle). Borrowed from English.
Play the triangle.
Triangular road sign, such as a yield sign.
There is a triangular sign ahead.
A triangular corner shelf or rack, often used in kitchens.
Put the sponge in the triangular corner rack.
Love triangle. The standard term for a romantic relationship involving three people.
They got caught in a love triangle.
三角形の面積を求めなさい。
Find the area of the triangle.