________________
OHAPTER VIN-QALOULATIONS REGARDING EXCAVATIONS. 263,
224. The length of a longish quadrilateral is 120 (dandas) and the breadth is 40. The ditch around is as big as 4 danlas in breadth and 3 in depth. (Find out the cubical contents.)
The rule for arriving at the value of the oubionl contents of an excavation, when the depth of the excavation varios (at various points), and also for arriving, when the cubioal contents of an excavation are known, at the depth of digging noocesory in the case of another (known) area (so that the oubical contents may be the same) :--
23}. The sum of the depths (measured in different places) is divided by the number of places; this gives rise to the (avorago) depth. This multiplied by the top area (of the oxcavation) gives rise to the (required) cubical contents of the excavation in the case where that area is trilateral, quadrilateral or circular. The cubical contente (of a given excavation), when divided by the (known) value of another area, gives rise to the depth (to which there should be digging, so that the resulting cubical contents may be the same).
Examples in illustration thereof.
241. In an equilateral quadrilateral field, the ground covered by which has an extent measured by 4 hartas (in longth and breadth), the excavations are (in depth) 1,2,3, and 4 hastas (in four different cases). What is the measure of the average depth of the excavations)?
254. There is a well with an equilateral quadrilateral section, the sides whereof aro 18 hastas in measure; its depth is 1 hantas. With the water of this (well), another woll measuring 9 hastas at each of tho sides of the section) is filled. What is the depth (of this other well)?
When the measnres of the sides of the top (sectional area) and also of the bottom (sectional aren) are known, and when the
297. Yor finding out the total fength of the surrounding ditoh whon the contral mon of earth is rectangular in section, the measures of the sidor M iporowsed by the width or hall the width of the ditch are added together, according tbe Ka mantika or tho Andra result is required.
