This short video and interactive assessment activity is designed to teach third graders an overview of ellipses, trapezoids, rhombi, and polygons.
This short video and interactive assessment activity is designed to teach third graders about determining whether lines are perpendicular.
This short video and interactive assessment activity is designed to teach third graders an overview of quadrilaterals.
This short video and interactive assessment activity is designed to give fourth graders an overview of quadrilaterals.
This short video and interactive assessment activity is designed to teach second graders about counting the number of different 2d shapes in a composite figure.
This short video and interactive assessment activity is designed to teach third graders about counting the number of basic 2d shapes in a composite figure.
This short video and interactive assessment activity is designed to teach fifth graders about identifying basic 2d shapes in composite figures.
This short video and interactive assessment activity is designed to give fourth graders an overview of reflective symmetry.
This short video and interactive assessment activity is designed to teach second graders about identifying parallel and perpendicular lines.
This short video and interactive assessment activity is designed to teach second graders an overview of quarter-circles and semi-circles.
This short video and interactive assessment activity is designed to give fourth graders an overview of quarter-circles and semi-circles.
This short video and interactive assessment activity is designed to teach third graders an overview of quarter-circles and semi-circles.
This short video and interactive assessment activity is designed to teach third graders an overview of reflective symmetry.
This short video and interactive assessment activity is designed to teach first graders an overview of quarter-circles and semi-circles.
This short video and interactive assessment activity is designed to teach third graders about identifying the properties of squares.
This task shows how to inscribe a circle in a triangle using angle bisectors. A companion task, ``Inscribing a circle in a triangle II'' stresses the auxiliary remarkable fact that comes out of this task, namely that the three angle bisectors of triangle ABC all meet in the point O.
This task is primarily for instructive purposes but can be used for assessment as well. Parts (a) and (b) are good applications of geometric constructions using a compass and could be used for assessment purposes but the process is a bit long since there are six triangles which need to be constructed.
This task provides an opportunity for students to apply triangle congruence theorems in an explicit, interesting context.
This problem introduces the circumcenter of a triangle and shows how it can be used to inscribe the triangle in a circle. It also shows that there cannot be more than one circumcenter.
This task focuses on a remarkable fact which comes out of the construction of the inscribed circle in a triangle: the angle bisectors of the three angles of triangle ABC all meet in a point.