Question

a lawn is in the shape of semi circle of diameter 35 dm.the lawn is surrounded by a flower bed of width 3.5 dm all around.find the area of flower bed in dm square

Answer 1

area of flower bed = πr²/2. where r =d/2

r=17.5dm

Answer 2

Answer:

$211.75 dm^2$

Step-by-step explanation:

Inner radius = $\frac{35}{2} = 17.5 dm$

We are given that .the lawn is surrounded by a flower bed of width 3.5 dm all around

Outer radius = 17.5 dm + 3.5 dm = 21 dm

Area of semicircle = $\frac{1}{2} \pi r^2$

Area of the flower bed = Outer area - inner area

                                      =$\frac{1}{2} \times \frac{22}{7}(21^2 - 17.5^2)$

                                      =$211.75 dm^2$

Hence the area of flower bed is $211.75 dm^2$