Geometry Basics

Drag segment CD onto AB and align one endpoint to compare their lengths directly and read the difference; then mark the midpoints and verify with equality ticks that the midpoint splits a segment into two equal parts.

Watch two angles combine into a right or straight angle: given angle α, pick its complement or supplement from three options, then watch the β-sweep animation fill the angle to see that everything is about the sum.

Meet the cube, cylinder, and cone with their flat nets: tap Unfold/Fold to watch the faces spread out and close up, then play the net-guessing quiz to build the connection between solids and flat patterns.