A fairly short biographical sketch of Willebrord Snell (1591-1626 CE). Discusses his upbringing, education and professional life.

Scroll down to Lesson 2 for a tutorial on image formation in plane mirrors. The tutorial from Glenbrook South High School provides lessons on why and how an image is formed, image characteristics for plane mirrors, ray diagrams, plus more.

Two hands-on lab activities for instructors to use when teaching about the coordinate graphs of the sine, cosine, and tangent functions derived from a unit circle. The graphs of the reciprocals of the three functions are investigated....

The learners will explore angles, rays, line segments, perpendicular lines, parallel lines, and two-dimensional figures through the use of the book Shape Up! Fun With Triangles and Other Polygons by David A. Adler. They will also...

The lesson discusses commonly used geometric terms. Definitions and examples of a line segment, ray, and angle are included.

[Free Registration/Login Required] In this lesson the teacher will use geometry and spatial sense to distinguish between point, ray, line, line segment and angle. The students will review vocabulary for these terms and then...

[Free Registration/Login Required] Students use the interactive features of Activstudio to identify and label one and two dimensional characteristics. Students explore rays, lines, end points, line segments, vertices, and angles.

Students make a series of geometric drawings of points, obtuse angles, rays, polygons, and the like. Each child is given one but not allowed to show anyone else. The drawing is then taped to the back of the child in front of them. The...