Flowerbed 22573

Around a round flowerbed with a diameter of 6m should be made a sidewalk with a width of 0.5m. How many square meters of material do we need?

Correct answer:

S =  10.2102 m²

Step-by-step explanation:

$$\begin{gathered} D=6\text{m} \\ h=0.5\text{m} \\ r=D/2=6/2=3\text{m} \\ {r}_2=r+h=3+0.5=\frac{7}{2}=3.5\text{m} \\ S=\pi \cdot r_2^2-\pi \cdot r^2=3.1416\cdot 3.5^2-3.1416\cdot 3^2=10.2102{\text{m}}^2 \end{gathered}$$

Try another example