Q. 19
Protul has drawn an equilateral triangle ABC picture beside of which length of each side is 10 cm. Sumita has drawn three circular arcs centering A, B, C with the length of radius 5 cm. and has coloured some portion at the middle. Let us write by calculating the area of coloured portion.
Answer :
Given: ∆ABC is an equilateral triangle with side 10 cm, Arcs centered at B and C have radius 5 cm.
We need to find the area of the colored portion.
Area of colored portion = Area of ∆ABC – Area of sectors centered at B and C.
∵ ∆ABC is an equilateral triangle
We know that
Area of a equilateral triangle
where a is the side of it.
⇒ Area of ∆ABC = 43.3cm2
For the sectors,
Radius = 5 cm and angle subtended = 60°
{∵∆ABC is an equilateral triangle and each angle of it is 60°}
We know that the area of the minor sector
⇒ Area of sector centered at
⇒ Area of sector centered at B =13.095 cm2
Total area of both the sectors centered at B and C = 13.095 + 13.095 = 26.19 cm2
⇒ Area of colored portion = 43.3 – 26.19 = 17.11 cm2
Rate this question :
Surface Area of Right Circular Cylinder49 mins
Surface Area of Right Circular Cylinder52 mins
Surface Area and Volume of Right Circular Cylinders42 mins
Surface Area and Volume of Right Circular Cone37 mins
Champ Quiz | Area of Triangle53 mins
Champ Quiz | Area of Parallelogram55 mins
Let's Understand Circular Motion39 mins
Quiz | Area and Parallelogram46 mins
Surface Area of Cube and Cuboid49 mins
Lets understand Circular Motion42 mins
The inner diameter and external diameter of an Iron ring plate are 20 cm and 22 cm. The quality of iron plate in the ring is
West Bengal MathematicsThe ratio of the area of an equilateral triangle inscribing a circle is
West Bengal MathematicsRabeya drew an equilateral triangle with sides 21 cm. on a big paper. Drawing a circle inscribing that triangle coloured the circular region. I write by calculating the area of coloured region.
West Bengal MathematicsThree circular plate were cut off from a tin plate with equal width if the ratio of length of diameter of three circles is 3:5:7, let us see by calculating the ratio of their weight.
West Bengal Mathematics