Shazli took a wire of length 44 cm and bent it into the shape of a circle. Find the radius of that circle. Also find its area. If the same wire is bent into the shape of a square, what will be the length of each of its sides? Which figure encloses more area, the circle or the square? (Take \(\pi\) = \(\frac{22}{ 7}\) )
Solution and Explanation
Circumference = \(2\pi r\) = \(44\) \(cm\)
= \(2\times \frac{22}{7}\times r=44\)
\(r=7\;cm\)
Area = \(\pi r^2\)
= \(\frac{22}{7}\times 7\times 7=154\;cm^2\)
If the wire is bent into a square, then the length of each side would be = \(\frac{44}{4}=11\; cm\)
Area of square = \((11)^2\) = \(121\) \(cm^2\)
Therefore, circle encloses more area.
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Match the items given in Column I with one or more items of Column II.
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(vi) -\(\frac{7}{12}\)÷(-\(\frac{2}{13}\))
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Concepts Used:
Circle
A circle can be geometrically defined as a combination of all the points which lie at an equal distance from a fixed point called the centre. The concepts of the circle are very important in building a strong foundation in units likes mensuration and coordinate geometry. We use circle formulas in order to calculate the area, diameter, and circumference of a circle. The length between any point on the circle and its centre is its radius.
Any line that passes through the centre of the circle and connects two points of the circle is the diameter of the circle. The radius is half the length of the diameter of the circle. The area of the circle describes the amount of space that is covered by the circle and the circumference is the length of the boundary of the circle.
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