9. Problem 52 from the Rhind Papyrus. Example of a cut-off (truncated) triangle of land. Suppose it is said to thee, What is the area of a cut-off triangle of land of 20 khet in its side, 6khet in its base, 4 khet in its cut-off line? Solution: Add its base to its cut-off line; it makes 10. Take ½ of 10, that is 5, in order to get its rectangle. Multiply 20 times 5; it makes 100 [square khets]. This is its area. This cut-off (truncated) triangle of land is a right trapezoid. Use the formula for the area of a trapezoid to verify that the solution above yields the area of the land.