Advertisements
Advertisements
प्रश्न
In the following figure, shows the cross-section of railway tunnel. The radius OA of the circular part is 2 m. If ∠AOB = 90°, calculate:
the area of the cross-section.
उत्तर
We have a cross section of a railway tunnel. `ΔOAB`is a right angled isosceles triangle, right angled at O. let OM be perpendicular to AB.
Area of cross section,
`3/4 ("Area of circle")+"Area o"f ΔOAB`
`=(pi)(2)^2(3/4)+1/2(2)(2)`
`=(3pi+2)m^2`
APPEARS IN
संबंधित प्रश्न
Find the cost of polishing a circular table-top of diameter 1.6 m, if the rate of polishing is ₹ 15/m2. (Take π = 3.14)
From a circular piece of cardboard of radius 3 cm two sectors of 900 have been cutoff . Find the perimeter of the remaining portion nearest hundredth centimeters ( `"Take" pi = 22/ 7`).
In the following figure, ABCD is a square of side 2a, Find the ratio between
(i) the circumferences
(ii) the areas of the in circle and the circum-circle of the square.
In the following figure, AB = 36 cm and M is mid-point of AB. Semi-circles are drawn on AB, AM and MB as diameters. A circle with centre C touches all the three circles. Find the area of the shaded region.
In the following figure, If ABC is an equilateral triangle, then shaded area is equal to
ABCD is a square of side 4 cm. If E is a point in the interior of the square such that ΔCEDis equilateral, then area of Δ ACE is
The short and long hands of a clock are 4 cm and 6 cm long respectively. Find the sum of distances travelled by their tips in 2 days.
A rope by which a cow is tethered is increased from 16 m to 23 m. How much additional ground does it have now graze?
A child draws the figure of an aeroplane as shown. Here, the wings ABCD and FGHI are parallelograms, the tail DEF is an isosceles triangle, the cockpit CKI is a semicircle and CDFI is a square. In the given figure, BP ⊥ CD, HQ ⊥ FI and EL ⊥ DF. If CD = 8 cm, BP = HQ = 4 cm and DE = EF = 5 cm, find the area of the whole figure.
If the perimeter of a semicircular protractor is 72 cm where `pi = 22/7`, then the diameter of protractor is ____________.
