Khan Academy
Khan Academy: Equal Parts of Circles and Rectangles
In this exercise, students practice identifying equal parts of circles and rectangles. Students receive immediate feedback and have the opportunity to get hints, watch a tutorial video, and try questions repeatedly.
CK-12 Foundation
Ck 12: Elem Math: Identifying Semi Circles and Quarter Circles
[Free Registration/Login may be required to access all resource tools.] The video defines a semi-circle and a quarter-circle and answers a question determining which object is a semi-circle. The video is followed by a series of practice...
CK-12 Foundation
Ck 12: Elem Math: Counting Semi Circles and Quarter Circles in Composite Figures
[Free Registration/Login may be required to access all resource tools.] The video defines composite figures, semi-circles, and quarter circles, then uses those definitions to determine how many semi-circles and quarter circles are in the...