Advertisements
Advertisements
प्रश्न
The perimeter of a semicircular plate is 108 cm. find its area.
Advertisements
उत्तर
The perimeter of a semi-circular plate = 108 cm
⇒ πr + 2r = 108 ...(r is radius of a circle )
⇒ r ( π + 2 ) = 108
⇒ r = ` (108)/( π + 2) = (108)/(22/7 + 2) = (108 xx 7) / (36) = 21 "cm"`
Now, area of a semi-ccircular pleate = `[πr^2]/2 = [22/7 xx 21 xx 21]/2 = 693 "cm"^2`
APPEARS IN
संबंधित प्रश्न
The perimeter of a rectangular board is 70 cm. Taking its length as x cm, find its width in terms of x.
If the area of the rectangular board is 300 cm2; find its dimensions.
Trapezium given below; find its area.
A wire when bent in the form of a square encloses an area of 484 m2. Find the largest area enclosed by the same wire when bent to from:
- An equilateral triangle.
- A rectangle of length 16 m.
The perimeter of a rhombus is 46 cm. If the height of the rhombus is 8 cm; find its area.
Two adjacent sides of a parallelogram are 24 cm and 18 cm. If the distance between the longer sides is 12 cm; find the distance between the shorter sides.
The rate for a 1.20 m wide carpet is Rs. 40 per meter; find the cost of covering a hall 45 m long and 32 m wide with this carpet. Also, find the cost of carpeting the same hall if the carpet, 80 wide, is at Rs. 25. Per meter.
Vertices of given triangles are taken in order and their areas are provided aside. Find the value of ‘p’.
| Vertices | Area (sq.units) |
| (p, p), (5, 6), (5, –2) | 32 |
Find the area of the quadrilateral whose vertices are at (– 9, – 2), (– 8, – 4), (2, 2) and (1, – 3)
Let P(11, 7), Q(13.5, 4) and R(9.5, 4) be the midpoints of the sides AB, BC and AC respectively of ∆ABC. Find the coordinates of the vertices A, B and C. Hence find the area of ∆ABC and compare this with area of ∆PQR.
PQRS is a rectangle formed by joining the points P(– 1, – 1), Q(– 1, 4), R(5, 4) and S(5, – 1). A, B, C and D are the mid-points of PQ, QR, RS and SP respectively. Is the quadrilateral ABCD a square, a rectangle or a rhombus? Justify your answer.
