For complete details see the referred web page. an excerpt is as under:
One of the oldest documents in existence is a papyrus roll written in Egypt around 1890 BC. This is sometimes called the Golenischev Papyrus, after the Russian who purchased it in Egypt in 1893 and brought it to Moscow, where it remains today. It is also commonly called the Moscow Papyrus. It's about 18 feet (544 centimeters) long, and about 4 centimeters wide, and the writings consist of 25 mathematical problems with solutions. By far the most intriguing of these is the 14th, which asks for the volume of a truncated pyramid (frustum). Roughly translated, it says
Given a truncated pyramid of height 6, base 4, and top 2, you are to square the bottom, multiply the bottom by the top, square the top, and add all these to give 28. Then you are to multiply this by a third of the height to give the right answer, 56.
The type of solid described in this problem is illustrated below, with a, b, and h signifying the linear measures of the top, bottom, and height respectively.
In modern notation the Egyptian method of finding the volume can be expressed by the formula