Display acute,obtuse,reflex angles

Learn to recognise acute, obtuse, reflex and right angles.

Create and investigate problems involving complementary or supplementary angles, intersecting lines and angles at a point. Angles can be automatically displayed or measured using a protractor. Works great on an interactive whiteboard.

Polyhedra plaited with paper strips

Use these instructions to construct geometric solids, or 3D geometric objects – polyhedra – from folded strips of paper.  The author provides detailed, illustrated instructions for constructing many polyhedra, among them a cube (hexahedron), triangular prism, pyramid (Tetrahedron), on up to an 18-sided solid.

Free Online Geometry Textbooks

This collection of geometry flexbooks includes online and downloadable editions of geometry textbooks covering topics from middle school geometry to advanced high school geometry postulates and theorems.  Several of the textbooks have both student and teacher editions.

Fractal Geometry

From site: Here we introduce some basic geometry of fractals, with emphasis on the Iterated Function System (IFS) formalism for generating fractals.

In addition, we explore the application of IFS to detect patterns, and also several examples of architectural fractals.

First, though, we review familiar symmetries of nature, preparing us for the new kind of symmetry that fractals exhibit.

Geometry Practice Problems

Mr. Martini’s Classroom provides an interactive review of geometry problems with points, lines and angles, angle measurement and use of a protractor, classifying polygons and finding perimeters, area of triangles and rectangles, classifying quadrilaterals and triangles, circles, circumference and area, and volume of solids.