Praxis Core Academic Skills for Educators: Mathematics (5733)GeometryHard

A geometer is analyzing a line segment on a coordinate plane. The segment connects point A (2, 5) and point B (8, 1). What is the length of this line segment?

  1. A√52 units
  2. B√68 units
  3. C√40 units
  4. D√32 units
Show answer & explanation

Correct answer: A. √52 units

The distance between two points (x1, y1) and (x2, y2) in a coordinate plane is given by the distance formula: d = √((x2 - x1)² + (y2 - y1)²). For points A(2, 5) and B(8, 1): d = √((8 - 2)² + (1 - 5)²) = √((6)² + (-4)²) = √(36 + 16) = √52 units.

Why the other options are wrong

  • B. Incorrect calculation; this would be (8-0)^2 + (1-0)^2 if from origin.
  • C. Incorrect calculation; perhaps (8-2)^2 + (1+5)^2 = 36+36=72.
  • D. Incorrect calculation; (8-2)^2 + (5-1)^2 = 36 + 16 = 52.

Distance Formula (Coordinate Geometry)

A formula used to find the distance between two points in a Cartesian coordinate system.

  • Derived from the Pythagorean theorem.
  • Formula: d = √((x2 - x1)² + (y2 - y1)²).
  • The order of (x1,y1) and (x2,y2) does not affect the final distance.

Memory trick: X difference squared, Y difference squared, add them, root them, distance is shared!

More Geometry questions