Free Algebra 1 Worksheets For 9th Grade | Printable Math ... Showing top 8 worksheets in the category - 9th Grade Algebra 1. Sum of the angles in a triangle is 180. Printable 9th grade algebra worksheets. Easily download and print our 9th grade math worksheets. 9th grade algebra worksheets with answers. You should use the worksheets to fix 9th Grade Algebra 1 Worksheets that your child may be having.