Acute angle

An acute angle is a type of angle that measures less than 90 degrees. Imagine the corner of a piece of paper or an open book—those are right angles, exactly 90 degrees. An acute angle is sharper and smaller than that, like the pointed tip of a slice of pizza or the hands of a clock at 10:10. It’s a common term in geometry used to describe angles that are "narrow" or "sharp." Understanding acute angles helps in studying shapes and their properties, especially in fields like architecture, engineering, and design.