253 215. The two lateral sides are (each) 13 in measure; the top- side is 4; and the base is said to be 14 in measure. In this case, what may be the diameter of the circle described about (such) a quadrilateral figure with two equal sides? 216. The top-side and the (two) lateral sides are each 25 in measure. The base is 39 in measure. Tell me (here) the measure of the diameter of the circle described about such a quadrilateral figure with three equal sides. 217. One of the lateral sides is 39 in measure; the other lateral side is 52 in measure; the base is 60 and the top-side is 25. In relation to this (quadrilateral figure), what is the value of the diameter (of the circumscribed circle) ? CHAPTER VII-MEASUREMENT OF AREAS 218. The measure of the side of an equilateral triangle is 6; and that of an isosceles triangle is 13, the base (in this case) being 10 in measure. Give out what the values are of the diameters of the circles described about these triangles. • 219 In the case of a triangle with unequal siles the two sides are 15 and 13 in measure; the base is 14. Tell me the value of the diameter of the circle described about it. 220. If you know the paisācika (processes of calculation), tell me after thinking well what may be the value of the diameter of the circle described about a (regular) six-sided figure having 2 as the measure of each of (its) sides. The rule for arriving at the numerical values of the base, of the top-side and the (other) sides of the eight (different) kinds of figures beginning with the square, which are inscribed in a regular circular figure having a diameter of known numerical value:- 221. The value of the given diameter (of the circle) is divided by the value of the (hypothetically) arrived diameter of the circle (described about an optionally chosen figure belonging to 220. The Kanarese commentary on this stanza works out this problem by pointing out that the diagonal of a regular hexagon is equal to the diameter of the circumscribed circle. 221. The rule follows as a matter of course from the similarity of the required and the optionally chosen figures.
