[Free Registration/Login may be required to access all resource tools.] Students watch a video and attempt practice problems on counting lines and curves in various two dimensional shapes.

[Free Registration/Login may be required to access all resource tools.] The video shows how to count the number of straight lines and curves in a given 2D figure. The video is followed by practice problems.

Test your geometry aptitude using this interactive matching game. Match pictures and symbols to the correct definition. Answers are verified immediately. Winners can earn as much as 10,000 dollars and have their name posted for the day.

This site describes lines and angles "as found in various plane (flat) geometric figures.".

On this one page website sharpen your logic, graphing and pattern recognition skills while working on this challenge. The solution is available to double check your solution.

In this activity, children will investigate the paths that marbles take once set into motion and then how to change those paths, noting if and how they change.

A knife with only one edge, which formed a straight line. The blade was pointed, and its back curved. It was used for a variety of purposes, but chiefly for killing animals either in the slaughter house, or in hunting, or at the altars...