Advertisements
Advertisements
प्रश्न
A wire, when bent in the form of a square; encloses an area of 196 cm2. If the same wire is bent to form a circle; find the area of the circle.
Advertisements
उत्तर
Area of Square = 196 cm2
Side of Square = `sqrt("Area")` = `sqrt(196)` = 14 cm
Perimeter of Square = 4 x 14 cm
i.e. length of wire = 56 cm
Circumference of circle = 56 cm
2πr = 56
`2 xx 22/7 xx r = 56`
`r = (56 xx 7)/(2 xx 22)`
`r = 98/11` cm
`therefore "Area of circle enclosed" = pir^2`
= `22/7 xx 98/11 xx 98/11`
= `2744/11`
= 249.45 cm2
APPEARS IN
संबंधित प्रश्न
Two concentric circles of radii a and b (a > b) are given. Find the length of the chord of the larger circle which touches the smaller circle.
A rectangular park is 100 m by 50 m. It is surrounding by semi-circular flower beds all round. Find the cost of levelling the semi-circular flower beds at 60 paise per square metre (use π = 3.14).
Two circular pieces of equal radii and maximum area, touching each other are cut out from a rectangular card board of dimensions 14 cm × 7 cm. Find the area of the remaining card board. (Use π = 22/7).
In the following figure, the boundary of the shaded region consists of four semi-circular arcs, the smallest two being equal. If the diameter of the largest is 14 cm and of the smallest is 3.5 cm, find
- the length of the boundary.
- the area of the shaded region.
If he area of a sector of a circle is \[\frac{7}{20}\] of the area of the circle, then the sector angle is equal to
The length of an arc of the sector of angle θ° of a circle with radius R is
The radius of a circular wheel is 42 cm. Find the distance travelled by it in :
(i) 1 revolution ;
(ii) 50 revolutions ;
(iii) 200 revolutions ;
The floor of the circular swimming pool whose radius is 7 m has to be cemented at the rate of ₹ 18 per m2. Find the total cost of cementing the floor
If the perimeter of a semicircular protractor is 72 cm where `pi = 22/7`, then the diameter of protractor is ____________.
The diameter of a circle whose area is equal to the sum of the areas of the two circles of radii 24 cm and 7 cm is ______.
