Quadrilateral explorer
Drag corners. Watch the math.
Drag any of the four vertices and watch sides, angles, diagonals, perimeter, and area update in real time. The tool classifies the shape — square, rectangle, rhombus, parallelogram, trapezoid, kite — as you go.
Classification
Parallelogram
Both pairs of opposite sides parallel and equal.
- Sides270, 152, 270, 152
- Angles118°, 62°, 118°, 62°
- Perimeter844 u
- Area37 800 u²
Why teachers love it
Built for the projector — and the back row.
Drag any vertex
All four corners are grab handles. Stretch, skew, mirror — the shape responds smoothly so the class can see how a property changes the moment a side moves.
Live measurements
Side lengths, interior angles, both diagonals, perimeter, and area are computed every frame. The angles always sum to 360°, just like the textbook says.
Auto-classification
The tool calls out exactly what kind of quadrilateral you've drawn — square, rectangle, rhombus, parallelogram, trapezoid, kite — and explains why.
Use it on day one for…
Classroom-ready ideas
Geometry: parallelogram → rhombus
Start from the parallelogram preset. Drag a vertex until all sides equal — watch the classification flip to ‘rhombus’ as the kids predict it.
Properties of a square
Square preset on screen. Drag one corner so it's no longer a right angle. Ask: what's it now? Reverse to recover.
Area exploration
Hold base and height of a rectangle constant, then slant the top. Class watches the area stay the same — a clean introduction to base × height.
Diagonals as a shape clue
Show the diagonals on. Build a kite, a rhombus, a rectangle. Discuss which diagonals are equal, perpendicular, or bisecting.
Ready to try it with your class?
Sign up as a teacher to unlock quadrilateral explorer and the rest of the teaching tools.