Advertisements
Advertisements
प्रश्न
The given figure depicts a racing track whose left and right ends are semicircular.
The distance between the two inner parallel line segments is 60 m and they are each 106 m long. If the track is 10 m wide, find:
(i) The distance around the track along its inner edge
(ii) The area of the track
[Use Π = 22/7]
उत्तर
Distance around the track along its inner edge = AB + arc BEC + CD + arc DFA
`= 106 + 1/2xx 2pir + 106+ 1/2 xx 2pir`
`= 212 +1/2 xx2xx22/7xx30+1/2xx2xx22/7xx30`
`= 212 + 2 xx 22/7 xx 30`
`= 212 + 1320/7`
`=(1484+1320)/7 = 2804/7 m`
Area of the track = (Area of GHIJ − Area of ABCD) + (Area of semi-circle HKI − Area of semi-circle BEC) + (Area of semi-circle GLJ − Area of semi-circle AFD)
`= 106xx80-106xx60+1/2xx22/7xx(40)^2 - 1/2xx22/7xx(30)^2+1/2xx22/7xx(40)^2-1/2xx22/7xx(30)^2`
`=106(80-60)+22/7xx(40)^2-22/7 xx (30)^2`
`= 106(20)+22/7[(40)^2-(30)^2]`
`= 2120 + 22/7(40-30)(40+30)`
`=2120+(22/7)(10)(70)`
=2120+2200
= 4320 m2
Therefore, the area of the track is 4320 m2.
APPEARS IN
संबंधित प्रश्न
In fig. 3, a square OABC is inscribed in a quadrant OPBQ of a circle. If OA = 20 cm, find the area of the shaded region. (Use π = 3.14)
Find the area of the shaded region in the given figure, if ABCD is a square of side 14 cm and APD and BPC are semicircles. [Use Π = 22/7]
In a circular table cover of radius 32 cm, a design is formed leaving an equilateral triangle ABC in the middle as shown in the given figure. Find the area of the design (Shaded region). [Use Π = 22/7]
In the given figure, ABC is a quadrant of a circle of radius 14 cm and a semicircle is drawn with BC as diameter. Find the area of the shaded region. [Use Π = 22/7]
Find the area of triangle whose base measures 24 cm and the corresponding height measure 14.5 cm.
The perimeter of a triangular field is 240m, and its sides are in the ratio 25:17:12. Find the area of the field. Also, find the cost of ploughing the field at ₹ 40 per `m^2`
In Fig. 7, PQ and AB are respectively the arcs of two concentric circles of radii 7 cm and
3.5 cm and centre O. If ∠POQ = 30°, then find the area of the shaded region. [User`22/7`]
The area of the square that can be inscribed in a circle of radius 8 cm is ______.
Find the area of the flower bed (with semi-circular ends) shown in figure.
Read the following passage:
Governing council of a local public development authority of Dehradun decided to build an adventurous playground on the top of a hill, which will have adequate space for parking. After survey, it was decided to build rectangular playground, with a semi-circular area allotted for parking at one end of the playground. The length and breadth of the rectangular playground are 14 units and 7 units, respectively. There are two quadrants of radius 2 units on one side for special seats. |
Based on the above information, answer the following questions:
- What is the total perimeter of the parking area?
- (a) What is the total area of parking and the two quadrants?
OR
(b) What is the ratio of area of playground to the area of parking area? - Find the cost of fencing the playground and parking area at the rate of ₹ 2 per unit.
