I nailed it Mr. Nelson #11

Author:nelsone

The altitudes of any triangle meet at a single point called the ORTHOCENTER. (An altitude is the perpendicular line segment from a vertex of a triangle to the opposite side of the vertex.)

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centripetal force
探究長方形對角線上的正方形數目
Experiments with Transformations in the Plane
Roll Dice
Flip 9 Coins

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(B) Slippery Slopes: Deriving the Derivative
Task B Q1
Bragg Reflection Demonstration

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Plane Figures or Shapes
Rectangle
Square
Prism
Rotation