Illustrative Mathematics
Finding an Unknown Angle
Teach your class how to apply their knowledge of geometry as they explore the unknown. In order to find an unknown angle, learners must understand that rectangles have four interior right angles, that right angles have 90 degrees, and...
Curated OER
Is This a Rectangle?
How do you show that something is a rectangle? This activity starts with four coordinate points and asks young geometers to explain whether they create a rectangle. Knowledge from both geometry and algebra come into play here, as well...
University of Cambridge
University of Cambridge: Nrich: Making Rectangles
On this one page website sharpen your logicand pattern recognition skills while working on this rectangle challenge. The solution is available to double check your solution.