Question

The diagram shows a semi circle inside a rectangle of length 150 m. The semi circle touches the rectangle at a b and c. Calculate the perimeter of the shaded region.

Answer 1

Answer:

Step-by-step explanation:

C=π×d=3.142×160=502.72

502.72/4=125.68cm

Because we can make from the rectangle two squares and then we would have 4 squares in total.

That is for 2 marks.If you have got any ideas for the other two marks,I would love to hear from you.I am doing the same question.Also,I see you have done question 7.Would you mind to help me with it?

Answer 2

Answer:

Perimeter of the shaded region is 268 m

Step-by-step explanation:

In this diagram a semi circle is drawn inside a rectangle of length 150m.

Length of diameter of a semicircle = 150 m

So radius of the semicircle = $\frac{150}{2}=75 m$

We have to find the perimeter of the shaded region.

Perimeter of the shaded region = length of tangents drawn on the circle at A and B + m(arc AB)

Length of tangents = radius of the semi circle = 75 m

and m(arc AB) = $\frac{\text{Perimeter of the circle}}{4}=\frac{2\pi r}{4}$

= $\frac{2\pi (75)}{4}$

= $\frac{2(3.14)(75)}{4}$\

= $\frac{471}{4}$

= 117.75 m

Now Perimeter of the shaded region = 75 + 75 + 117.75

P = 267.75 ≈ 268 m