Q.1. All the vertices of a rhombus lie on a circle. Find the area of the rhombus, if area of the circle is 1256 cm2 (Use π = 3.14).
Ans. Area of the circle = 1256 cm2
⇒ A = πr2
A.T.Q. 1256 = πr2
Here, Diagonals of rhombus = diameter of the circle
Q.2. Find the number of revolutions made by a circular wheel of area 1.54 m2 in rolling a distance of 176 m.
Ans. Area of wheel = 1.54 m2
A = πr2
1.54 = πr2
Distance covered in one revolution = 4.4 m
No. of revolutions
Q.3. An archery target has three regions formed by three concentric circles as shown in Fig. If the diameters of the concentric circles are in the ratio 1 ; 2 : 3, then find the ratio of the areas of three regions.
Ans. Let, diameter of inner most circle = x
Diameter of middle circle = 2x
Diameter of outer most circle = 3x
∴ Area of inner most circle = π(x)2
Area of middle circle =
Area of outer most circle =
Ratio of the areas of three regions.