Question

23. A wire is bent to form four semi-circles as shown in figure. Find the length of the wire.
7 cm
7 cm
7 cm
7 cm
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Answer 1

The length of the wire will be equal to the circumference of four semicircles that were made from it.

So, if the diameter of one semicircle is 32 cm, then the radius is = 32/2 cm = 16 cm.

Now, the circumference of a circle is 2*(pi)*(radius).

Here we have a semi-circle, so its circumference is half of of a circle = (pi)*(radius).

Then, circumference of 4 semi-circles is = 4*(pi)*(radius).

The value of pi is 22/7.

So, length of wire is = 4*(22/7)*16 cm = 200 cm (after rounding to the nearest hundreth).