In reference to a circle the value of is equal to

Ratio of areas of ∆MNO, ∆MOP and ∆MPQ in Fig. 9.18 is

In Fig. 9.19, EFGH is a parallelogram, altitudes FK and FI are 8 cm and 4cmrespectively. If EF = 10 cm, then area of EFGH is

Circumference of a circle is always

Area of triangle PQR is 100 cm² (Fig. 9.20). If altitude QT is 10 cm, then its base PR is