Question : A cone is formed with an arc length AB equal to 20 cm. As the cone is formed from a sector of a circle with angle 72 degrees, determine
a) the radius of the circle from which the sector is taken, and
b) the radius of the base of the cone formed by sector ABC
a) the radius of the circle from which the sector is taken, and
b) the radius of the base of the cone formed by sector ABC
ANSWER:
(a) Step1: Given, Arc Length=20cm
Angle = 72 degrees
Required = Radius( r )
Step2: Circumference = 2Pi*r
arc length = (x/360 degrees) * 2Pi*r
Step3:Putting the values
20 = (72/360)*2Pi*r --------[pi=22/7=3.14]
r = 15.915 cm
1(b) Step1: Given, Same as 1(a)
Required =the radius of the base of the cone
Step2: circumference = 2Pi*r base of cone = circumference
Step3:Putting the values
20 cm = 2Pi*r
r = 10/Pi
r = 3.18 cm
Angle = 72 degrees
Required = Radius( r )
Step2: Circumference = 2Pi*r
arc length = (x/360 degrees) * 2Pi*r
Step3:Putting the values
20 = (72/360)*2Pi*r --------[pi=22/7=3.14]
r = 15.915 cm
1(b) Step1: Given, Same as 1(a)
Required =the radius of the base of the cone
Step2: circumference = 2Pi*r base of cone = circumference
Step3:Putting the values
20 cm = 2Pi*r
r = 10/Pi
r = 3.18 cm
No comments:
Post a Comment