Advertisements
Advertisements
प्रश्न
The areas of two circles are in the ratio 9 : 4. The ratio of their circumferences is
पर्याय
3 : 2
4 : 9
2 : 3
81 : 16
उत्तर
Let the the radii of the two circles be r and R, the circumferences of the circles be c and C and the areas of the two circles be a and A.
Now,
`"a"/"A" = 9/4`
`=>(pi"r"^2)/(pi"R"^2) = (3/2)^2`
`=>"r"/"R" = 3/2`
Now, the ratio between their circumferences is given by
`c/C = (2pi"r")/(2pi"R")`
`="r"/"R"`
`=3/2`
Hence, the correct answer is option (a)
APPEARS IN
संबंधित प्रश्न
In Fig. 3, APB and AQO are semicircles, and AO = OB. If the perimeter of the figure is 40 cm, find the area of the shaded region [Use `pi=22/7`]
A wire is looped in the form of a circle of radius 28 cm. It is re-bent into a square form. Determine the length of the side of the square.
Saima wants to put a lace on the edge of a circular table cover of diameter 1.5 m. Find the length of the lace required and also find its cost if one meter of the lace costs ₹ 15. (Take π = 3.14)
Find the circumference and area of circle of radius 4.2 cm
Find the perimeter of a semicircular protractor whose diameter is 14 cm.
The perimeter of a sector of a circle of radius 5.6 cm is 27.2 cm. Find the area of the sector.
The circumference of a circular field is 308 m. Find is:
(i) Radius
(ii) Area.
The area of a circular playground is 22176 m2. Find the cost of fencing this ground at the rate of Rs 50 per metre.
The distance around a circle is its ______.
The moon is about 384000 km from earth and its path around the earth is nearly circular. Find the length of path described by moon in one complete revolution. (Take π = 3.14)
