Angles and Protractor

Here you can measure angles with an instrument called a protractor. Instead of dividing the circle into only twelve hours, the protractor divides the circle into 360 units called degrees.

When you press the "show me how" button, you can see how the protractor can be compared to the angle. The part of the circle that matches the angle will be entered into the "degrees" text box.

Click "my turn" if you want to try matching the same angle again. Click "next" to try a new angle.

Since there wasn't room to draw all the numbers from 0 to 359 around the circumference of the circle, the protractor only shows every tenth number. Notice that a protractor starts with a zero at the top. How does this compare with a clock? What's different about the way the numbers appear?

Leone Learning Systems, Inc. (LLS) is a North Shore company that provides online courses for kids anywhere and local teaching and tutoring services for students in Chicago and the Northern Suburbs of Chicagoland. LLS also provides a free geometry software package for children age 6 and up, and free resources for teachers and parents. This site includes information about classes taught, availability for tutoring, learning activities for kids, lesson plans, and an ongoing software and curriculum research and development effort.