Question

Find the perimeter and area of the following using pie=3.14

Answer 1

To solve this question we will use the following diagram:

From the diagram, we get that the diameter of the semicircle is 8cm.

The perimeter of the figure is:

$P=14\operatorname{cm}+4\operatorname{cm}+6\operatorname{cm}+\pi\cdot8\operatorname{cm}\text{.}$

Substituting π=3.14 and simplifying we get:

$\begin{gathered} P=14\operatorname{cm}+4\operatorname{cm}+6\operatorname{cm}+25.12\operatorname{cm}, \\ P=49.12\operatorname{cm}\text{.} \end{gathered}$

Now, the area of the given figure is the area of the rectangle plus the area of the semicircle:

$A=14\operatorname{cm}\times4\operatorname{cm}+\frac{\pi\cdot(4\operatorname{cm})^2}{2}\text{.}$

Substituting π=3.14 and simplifying we get:

$\begin{gathered} A=56cm^2+25.12cm^2, \\ A=81.12cm^2. \end{gathered}$

Answer:

$\begin{gathered} \text{Perimeter}=\text{ 49.12cm,} \\ \text{Area}=\text{ 81.12 cm}^2. \end{gathered}$