Theorem 9.2 : Two triangles on the same base (or equal bases) and between the same parallels are equal in area.

Parallelogram on equal bases and between the same parallels are equal in area.

Triangles on the same base and between the same parallel are equal in area.

Triangles on the same base and between the same parallels are equal in area.

Prove that two triangles on the same base and between the same parallels are equal in area.

Theorem 9.3 : Two triangles having the same base (or equal bases) and equal areas lie between the same parallels.

Two Trinangle having the same base and equal areas lie between the same parallels.

A |gm and a rectangle on the same base and between the same parallels are equal in area

Parallelograms on the same base and between the same parallel are equal in area.