Su Jiaoban fifth grade first volume math book 67 pages thinking questions.
4 (based on four sides) *3 (based on three vertices on the bisector) +2 (based on the bisector) *6 (based on six vertices on two parallel sides) +2 (based on half of four sides) *4 (based on four sides) *2 (based on two points on the other half of another parallel side) =40.