Advertisements
Advertisements
प्रश्न
AC and BD are two perpendicular diameter of a circle ABCD. Given that the area of shaded portion is 308 cm2 calculate:
(i) The length of AC and
(ii) The circumference of circle
उत्तर
(i) Let r be the radius of the circle.
Then `1/2 π r^2` = 308
r2 = 308 x 2 x `7/22` = 142
r = 14 cm
Now, AC = 2r = 28 cm
(ii) Circumference = 2πr
Circumference = `22/7` x 28
Circumference = 88 cm
APPEARS IN
संबंधित प्रश्न
In PSR, RTQ and PAQ are three semicircles of diameters 10 cm, 3 cm and 7 cm respectively. Find the perimeter of the shaded region. [Use π=3.14]
A car has wheels which are 80 cm in diameter. How many complete revolutions does each wheel make in 10 minutes when the car is travelling at a speed of 66 km per hour ?
A sector is cut from a circle of radius 21 cm. The angle of the sector is 150º. Find the length of its arc and area.
The minute hand of a clock is 10cm long. Find the area of the face of the clock described by the minute hand between 9 A.M. and 9.35 A.M.
A doorway is decorated as shown in the figure. There are four semi-circles. BC, the diameter of the larger semi-circle is of length 84 cm. Centres of the three equal semicircles lie on BC. ABC is an isosceles triangle with AB = AC. If BO = OC, find the area of the shaded region. (Take `pi = 22/7`)
Find in terms of x the length of the arc that subtends an angle of 30°, at the centre of circle of radius 4 cm.
The outer circumference of a circular race track is 528m. The track is everywhere 14m
wide. Calculate the cost of leveling the track at rate of 50 paise per square metre.
Find the area of the rhombus, the length of whose diagonals are 30 cm and 16 cm. Also, find the perimeter of the rhombus.
Choose the correct alternative answer for the following question.
A cone was melted and cast into a cylinder of the same radius as that of the base of the cone. If the height of the cylinder is 5 cm, find the height of the cone.
In the given figure, APB and AQO are semicircles and AO = OB. If the perimeter of the figure is 40 cm, find the area of the shaded region.
The sum of the radii of two circles is 7 cm, and the difference of their circumferences is 8 cm. Find the circumference of the circles.
The areas of two circles are in the ratio 9 : 4. The ratio of their circumferences is
Find the curved surface area , the total surface area and the volume of a cone if its :
Height = 8 cm , diameter = 12 cm
Find the diameter of the sphere for the following :
Volume = `72pi "cm"^3`
The shaded portion of the figure, given alongside, shows two concentric circles. If the circumference of the two circles is 396 cm and 374 cm, find the area of the shaded portion.
An express train is running between two stations with a uniform speed. If the diameter of each wheel of the train is 42 cm and each wheel makes 1200 revolutions per minute, find the speed of the train.
The circumference of a circle exceeds its diameter by 18 cm. find the radius of the circle.
The speed of a car is 66km per hour. If each wheel of the car is 140cm in diameter, find the number if revolution made by each wheel per minute.
Diameters of different circles are given below. Find their circumference (Take π = `22/7`)
d = 70 cm
The numerical value of the area of a circle is greater than the numerical value of its circumference. Is this statement true? Why?
