This Grade 3 perimeter - finding missing side length worksheet includes: finding a missing side length of polygons/quadrilaterals when given the perimeter and other side lengths. using a perimeter formula to find a missing side length.solving a perimeter story/word problem.This grade 3 perimeter-finding missing side length worksheet can be used as independent work, review, homework, or even as a quick quiz/assessment. It is grade 3 perimeter standards aligned. But, it can be used as enrichment i