252 GANITASARASANGRAHA An example an 8tration thereof. 2111-212d. The man who travels to the east moves at the rate of 2 ४jono8 (a day) ; and the other man who travels horth. wards moves at the rate of 8 ocus (a day). This (latter man) having thus moved on for 5 days turns to move along the hypo. tenuse. In how many days will he meet the (other) man ? Both (of them) move out at the same time, and the number of days spent (by both of them) in journeying out is the same. The rule for arriving at the numerical value of the diameters of circlos described about Bhe eight kinds of figures consisting of the five kinds of quadrilateral figures and the three kinds of triangular figures (already mentioned) 2134. In the case of a quadrilateral figure, the value of the diagonal (thereof), divided by that of the perpendicular, and (then) multiplied by that of the lateral side, gives rise to the value of the diameter of the circumscribed circle. In the case of a trilateral figure, the product of the values of the two sidos (other than the base) divided by the value of the perpendicular (gives rise to the required diameter of the circumscribed circle). Examples in allustration thereof. 2144. In the case of an equilateral quadrilateral figure having 8 as the measure of each of (its) side, and also in the case of another (quadrilateral figure) of which the vertical side measures 5 and bhe horizontal side measures 12, what is the measure (of the diameter) of the circumscribed circle? 21B}. Let ABC be a triangle inscribed in a circle, AD 6he diameter thereofand BE bhe perpendicular on AC. Join BD. Now the triangles ABD and BBC are similar A B: AD=BG : BC A B BC AD B3 This is the formula given in the rule A for the diameter of a circle circumaoribed about a quadrilateral or a triangle
