1. a mathematical statement that has been proven to be true based on previously established statements and accepted mathematical principles
Usage: mathematics
2. a general principle or rule that can be proven or demonstrated
Usage: formal

Examples

• The Pythagorean theorem states that in a right triangle, the square of the hypotenuse equals the sum of squares of the other two sides.
• Students spent weeks learning to prove geometric theorems.
• Einstein’s theorem revolutionized our understanding of space and time.
• The professor asked us to memorize several important theorems for the exam.
• This theorem can be applied to solve many different types of problems.
• The mathematician published a new theorem about prime numbers.