4th Grade Math Worksheets, Math Worksheets for Grade 4 - BYJU'S ... Measuring Angles. Grade 4 Math Worksheets for geometry help your child learn to measure angles using a protractor and classify them as acute, right, or obtuse angles. All Grade 4 Math Worksheets are comprehensively detailed. They can help your child master fourth grade math concepts, and then apply and practice them in an easy and fun-filled way.