Definition

Noun: A triangle that contains no right angle. This means all three interior angles are either all acute (each less than 90 degrees) or one is obtuse (greater than 90 degrees).

Usage

The term "oblique triangle" is used in geometry to classify triangles based on their angles. It is the general category for any triangle that is not a right triangle.

Examples

• In trigonometry, the laws of sines and cosines are used to solve oblique triangles.
• An equilateral triangle, where all angles are 60 degrees, is a specific type of oblique triangle.
• To find the area of an oblique triangle, you can use the formula ½ * a * b * sin(C).

Advanced Usage

• Oblique Spherical Triangle: In spherical geometry, this refers to a triangle on a sphere's surface that does not contain a right angle.
• The problems involving oblique triangles are often termed "oblique cases" in trigonometry, requiring methods different from the simple ratios used for right triangles.

Variants and Related Words

• Acute Triangle: A specific type of oblique triangle where all three interior angles are acute (less than 90 degrees).
• Obtuse Triangle: A specific type of oblique triangle that has one interior angle greater than 90 degrees.
• Right Triangle: The antonym; a triangle that contain a right angle (90 degrees).

Synonyms

• Non-right triangle

Antonyms

• Right triangle
• Right-angled triangle

Noun

1. a triangle that contains no right angle