Question

There is a circular running track. The ends are semicircle of radius 30m. The straights are 40m in length (each one). Find the area bounded by the track.

Answer 1

444m2
ncert 11th exercise 12.3 question 6

Answer 2

Answer:

The area bounded by the track is 5226m²

Step-by-step explanation:

Tip:

• The area bounded by the track would consist of a rectangle and 2 hemisphere.
• The area of rectangle is given by

        $Area=length$ × $Breadth$

• Area of semicircle is $\pi \frac{r^{2} }{2}$

Step 1 of 2:

• Given length of straight line is 40m.
• Diameter of the Semicircle will become the breadth of rectangle i.e. 60m.
• The area of rectangle  is given by  

      $Area=length$ × $Breadth$

      $=40$×$60$

      $=2400$

Step 2 of 2:

• Area of Semicircle is $\pi \frac{r^{2} }{2}$
• No of Semicircle=2
• Area =$2$ × $\pi \frac{r^{2} }{2}$

      $= 2\pi \frac{30^{2} }{2} \\=2826$

• The area bounded by track is

      $=2826+2400\\=5226$