also: さしがた
矩形の面積を計算してください。
Please calculate the area of the rectangle.
square wave; rectangular wave
Standard kanji form; the reading くけい is the most common.
Rare reading; くけい is overwhelmingly more common.
矩 means 'carpenter's square' or 'rule', and 形 means 'shape'. Together they denote a shape with right angles, i.e., a rectangle.