Question

The ratio of the radii of two hula-hoops is 3:4.
is the ratio of their circumferences?
(a) 1:2
(b) 2:4
(c) 3:4
(d) 4:3

Plz answer​

Answer 1

The ratio of the radii of two hula hoop is 3 : 4.
Radius of 1st hula hoop=3x
Radius of 2nd hula hoop=4x

Circumference = 2πr

C1/C2 = 2πr1/2πr2

C1/C2 = 2π3x/2π4x

C1/C2= 3/4

The ratio of their circumferences is 3/4.

Answer 2

The ratio of the circumference will be $3:4$.

The formula of the circumference :

$2\pi r$

Solution -

The ratio of the radii of two hula hoops is $3:4$.

The radius of 1st hula hoop $= 3x$.

The radius of 2nd hula hoop $= 4x$.

Circumference $= 2\pi r$

$C1/C2 = 2\pi r1/2\pi r2\\C1/C2 = 2\pi 3x/2\pi 4x\\C1/C2= 3/4$

Therefore, the ratio of the circumference is $3/4$ that is $3:4$.

#SPJ2