Today i am solving ncert class 10 chapter areas related to circles its very hard to solve please give me the solution of exercise 12.2 question number 10 . find the best solution of this question. An umbrella has 8 ribs which are equally spaced (see Fig. 12.13). Assuming umbrella to be a flat circle of radius 45 cm, find the area between the two consecutive ribs of the umbrella.