What is a Right Angle?
A right angle is a fundamental concept in geometry that measures exactly 90 degrees (90°). It is formed by the intersection of two perpendicular lines and is often symbolized by a small square at its vertex instead of a curved arc.
Section 2: Identifying a Right Angle
A key characteristic of a right angle is that it represents a quarter of a full turn or a full circle (360° / 4 = 90°). Lines that meet at a right angle are called perpendicular lines. Angles smaller than a right angle are called acute angles, and angles larger than a right angle (but less than 180°) are called obtuse angles.
Section 3: A Practical Example
Right angles are extremely common in the world around us. For example, the corner of a square or a rectangle is a right angle. The corner where a wall meets the floor, the corner of a book page, and the intersection of the horizontal and vertical lines on a grid are all practical examples of right angles.
Section 4: Why Are Right Angles Important?
Right angles are a cornerstone of geometry, construction, and design. They provide stability and predictability in structures, from the frame of a house to the layout of a city grid. They are also essential for concepts like the Pythagorean theorem and trigonometry, which are used in fields like engineering, architecture, and physics.