Pythagorean Theorem:In geometry, this theorem states that in a right triangle, where "a" and "b" are legs (sides adjacent to right angle) and "c" is hypotenuse (side opposite to right angle), it holds true that `a^2 + b^2 = c^2`. This theorem can be used to find straight-line distances.
Vector: A vector represents both magnitude (size) and direction. In this context, a vector can be used to represent the straight-line distance between two points.
Cartesian Coordinates:A coordinate system that uses perpendicular axes (x and y) to locate points on a plane. It can be used to calculate the straight-line distance between two points using the Pythagorean theorem.