IXL – Grade 4, Unit 1 IXL msad51 sign in – Level F P.1Identify planar and solid figures P.2Types of triangles P.3Open and closed shapes and qualities of polygons P.4Which 2-dimensional shape is being described? P.6Classify quadrilaterals P.7Number of sides in polygons P.9Similar and congruent P.11Acute, right, obtuse, and straight angles