Key Idea: Slant Height
For pyramids and cones, the slant height is the distance along the face from the base to the apex (tip).
General Rule:
Often found using the Pythagorean Theorem:
(Slant Height)^2 = (Height)^2 + (Half of Base Length or Radius)^2
Represents the hypotenuse of a right triangle formed by the height and half the base (or radius).
Why this matters for the SAT:
Slant height is needed to calculate lateral surface area of pyramids and cones.
Recognizing it and using the Pythagorean Theorem prevents mistakes in geometry problems involving 3D shapes.