Final answer:
A right angle in geometry is an angle of 90 degrees, indicating a perpendicular relationship. It is crucial in trigonometry, which involves studying angle and side relationships in right-angled triangles, often using the Pythagorean Theorem.
Step-by-step explanation:
In geometry, a right angle is an angle of exactly 90 degrees, signifying a perpendicular relationship between two lines or planes. This concept is central to trigonometry, which studies the relationships between the angles and sides of right-angled triangles. In trigonometry, important ratios such as sine, cosine, and tangent are used to describe these relationships without requiring units, as they are merely ratios. The Pythagorean Theorem is a key principle in understanding right triangles, stating the relationship between the lengths of the sides of a right-angled triangle.
For instance, when considering a vector A and its components Ax and Ay along the x- and y-axes respectively, these three vectors form a right triangle if and only if Ax and Ay are perpendicular, thus creating a right angle between them.