1sorry i think so its pi-2
help me out on these ones....
1)The perimeter of the sector of a cricle is equal to the circumference of the semi circle of the same radius.Find in circular measure the angle subtended at the centre by bounding radii of the sector?
2)Two circles of equal radii pass through each other's centre.show that the length of the arc cut off from any circle by the other is equal to one third the length of its circumference?
plz elaborate....
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3 Answers
62part 2 is not very difficult..
The distnace between the centers of the circle is R
Also if you look at the triangle formed by the line joining the center of the circle to the points of intersection of the circles, the triangle formed will be such that the perpendicular distance is R/2 (Because half the distance between the centers)
hence the Sin Theta is 1/2
Hence the angle there is 30
Two times this is 60
hence the angle at the center is 120 which is 1/3rd of 360
Hence proved.
1is the answer of the first problem is pi -1
then i can help it out