15. A wire of length 121 cm is bent so as to lie along the arc of a ci

1.	15. A wire of length 121 cm is bent so as to lie along the arc of a circle of radius180 cm. Find in degrees, the angle subtended at the centre by the arc.
Answer» circumference of circle having R = 180cm = 2π180 = 360π cm now, 360π cm makes .. 360° angle.. so, 1 cm → 360/360π = 1/π ° angle..so, 121cm → will make 121/π ° angle = 38.51 °

15. A wire of length 121 cm is bent so as to lie along the arc of a circle of radius180 cm. Find in degrees, the angle subtended at the centre by the arc.

Answer»

circumference of circle having R = 180cm = 2*π*180 = 360π cm

now, 360π cm makes .. 360° angle..

so, 1 cm → 360/360π = 1/π ° angle..so, 121cm → will make 121/π ° angle = 38.51 °