CLASS10
BOARD: CBSE
Mathematic Worksheet  11
TOPIC: Circle
For other CBSE Worksheet for class 10 Mathematic check out main page of Entrancei.
FORMULAE
Page 187 n 188 Diagram in each block
1. Area of right angled triangle A = 1/2 a b Perimeter P = a + b+ c 
6. Parallelogram A = b × h P = Sum of all four sides 
2. Scalene triangle with sides a, b, c Semiperimeter s = a+b+c/2, Area A=√(s(sa)(sb)(sc)) Perimeter P= a + b + c 
7. Trapezium A = h/2(a + b) 
3. Isosceles right angled triangle A =1/2a^{2} P = a + a + d = 2a+ d

8. Quadrilateral whose longer diagonal d and the lengths of perpendiculars from opposite vertices h_{1} and h_{2}are given A = d/2 ( h1 + h2) 
4. An equilateral triangle A = ; P = 3a ; AM =√3/2 a 
9. Circle d = 2r or r =d/2 =2Π^{2} circumference C = 2 2Π r 
5. Rhombus whose diagonals are and A = 1/2d_{1}d_{2} ; P = 4a Side =√((d_{1}/2)^{2}+(d_{2}/2)^{2} ) 
10. Radius of in circle of a triangle =(Area of triangle)/(semiperimeter of the triangle) 
1. ABC is a triangle with AB = 10 cm, BC = 8 cm and AC = 6 cm. Three circles are drawn touching each other with the vertices as their centres. Find the radii of the three circles.
2. The radii of two wheels of a tractor is 0.96 m. For a certain distance the rear wheel makes 50 revolutions, while the front wheel makes 150 revolutions. What is the diameter of the front wheel?
3. It is proposed to add to a square lawn measuring 58 m on a side, two circular ends. The centre of each being the point of intersection of the diagonals of the square. Find the area of the whole lawn.
4. The length of a wire which is tied as a boundary of a semicircular park is 72 m. Find the radius of the semicircular park and area of the park.
5. A and B are the centres of two circles of radii 9 cm and 2 cm such that AB = 13 cm and , where C is the centre of another circle which touches the above two circles. Find the area of the circle with centre C.
6. Find the area enclosed between two concentric circles of radii 3.5 m and 7 m. A third concentric circle is drawn outside the 7 m circle so that area enclosed between it and the 7 m circle is same as that between the two inner circles. Find the radius of the third circle correct to two decimal place. (Take = 22/7)
7. The area enclosed between the circumferences of two concentric circles is 2464 m^{2} . If their radii are in the ratio 5: 3, calculate:a) the area of outer circle, b) the circumference of the inner circle.If a third circle is drawn outside the larger circle so that the area enclosed between this circle and the larger circle is twice the area enclosed between the given circles. Calculate the total area of this circle.
8. The largest area of an equilateral triangle, which can be formed by a given length of a wire, is 484√3 cm^{2}. If the same wire is bent twice, first to form a circle and then a square; find the ratio of the areas of circle and square.