a four-sided polygon
"When drawing the blueprint for the new garden, I realized that planting beds arranged in a simple quadrangle would maximize our available space."
a rectangular area surrounded on all sides by buildings
"The students gathered in the quadrangle for lunch, enjoying the shade between the four surrounding college buildings."
A geometric shape with four angles and four straight sides; a four-sided polygon.
"The blueprint shows that the garden is shaped as a quadrangle, with each corner meeting at a perfect right angle."