Right Angle

Definition

A right angle is an angle that measures exactly 90 degrees. It is one of the fundamental geometric angles and plays a crucial role in the study of properties related to angles, triangles, and other polygons.

5 Must Know Facts For Your Next Test

1. The symbol for a right angle is a small square or a 90-degree angle marker.
2. Right angles are essential in the Pythagorean Theorem, which relates the sides of a right triangle.
3. Rectangles and squares are examples of quadrilaterals that have four right angles.
4. The diagonals of a rectangle bisect each other at right angles.
5. The interior angles of a right triangle always add up to 90 degrees.

Review Questions

• Explain how the properties of right angles are used in the Pythagorean Theorem.
  • The Pythagorean Theorem states that in a right triangle, the square of the length of the hypotenuse (the side opposite the right angle) is equal to the sum of the squares of the lengths of the other two sides. This relationship is only true because the right angle ensures that the two shorter sides are perpendicular to each other, allowing the theorem to be applied. The right angle is a fundamental component of the Pythagorean Theorem and its applications in various geometric and trigonometric problems.
• Describe how right angles are used to define the properties of rectangles and squares.
  • Rectangles and squares are quadrilaterals that have four right angles. This means that the opposite sides of these shapes are parallel and the angles between adjacent sides are all 90 degrees. The presence of right angles in rectangles and squares allows for the derivation of their other properties, such as the equality of opposite sides, the bisection of diagonals at right angles, and the relationship between the lengths of the sides and the area of the shape.
• Analyze the role of right angles in the context of triangles and their classification.
  • In the classification of triangles, a right triangle is a triangle that has one angle that measures exactly 90 degrees. This special type of triangle allows for the application of the Pythagorean Theorem and the use of trigonometric functions to solve various problems involving the relationships between the sides and angles of the triangle. The presence of a right angle also affects the classification of other types of triangles, such as acute triangles and obtuse triangles, based on the measure of their angles.

Related terms

Acute Angle:

An angle that measures less than 90 degrees.

Obtuse Angle:

An angle that measures more than 90 degrees.

Perpendicular Lines:

Two lines that intersect at a right angle, forming four right angles.