Construct, measure, and explore geometric shapes and theorems on an interactive canvas. Drag points to see everything update in real-time.
In a right triangle, the square of the hypotenuse equals the sum of squares of the other two sides. Drag the vertices to see the relationship update live.
The inscribed angle is half the central angle subtending the same arc. A tangent is perpendicular to the radius at the point of tangency. Drag points around the circle to explore.
Every triangle has four classic centers: centroid (medians), circumcenter (perpendicular bisectors), incenter (angle bisectors), and orthocenter (altitudes). Toggle each to see them as you drag vertices.
When a transversal crosses two parallel lines it creates 8 angles. Alternate interior, alternate exterior, corresponding, and co-interior angle pairs have special relationships. Drag to see them change.
An exterior angle of a triangle equals the sum of the two non-adjacent (remote) interior angles. Drag the vertices to verify.