Question

find the perimeter and area of a semicircle whose radius is 3.5 CM

Answer 1

Answer:

P = 18cm

A = 19.25cm^2

Step-by-step explanation:

r = 3.5cm

Perimeter of semicircle = r [2+π]

P = 3.5 [2+22/7]

P = 3.5 x 36/7 = 18cm

Area of Semicircle = 1/2πr^2

A = 1/2 x 22/7 x (3.5)^2

A = 22/14 x 12.25

A = 269.5/14 = 19.25cm^2

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Answer 2

Given : A semicircle whose radius is 3.5 cm.

To find : The perimeter and area of the semicircle.

Solution :

We can simply solve this mathematical problem by using the following mathematical process. (our goal is to calculate the area and perimeter of the semicircle)

Here, we will be using the following mathematical formulas.

• Area of a semicircle = $\frac{π × {(radius)}^2}{2}$
• Perimeter of a semicircle = (π × radius) + (2 × radius) = radius × (π + 2)

By, putting the available data in the above mentioned mathematical formula we get,

Area of the given semicircle = $\frac {π × {(3.5)}^2}{2}$

or, Area of the given semicircle = $\frac{\frac{22}{7} \times {(3.5)}^2}{2}$

or, Area of the given semicircle = $\frac{38.5}{2}$

or, Area of the given semicircle = 19.25 cm²

And,

Perimeter of the given semicircle = 3.5 × (π + 2)

or, Perimeter of the given semicircle = 3.5 × $(\frac{22}{7} + 2)$

or, Perimeter of the given semicircle = 3.5 × $(\frac{22+14}{7} )$

or, Perimeter of the given semicircle = 3.5 × $(\frac{36}{7})$

or, Perimeter of the given semicircle = 18 cm

Hence, the area of the given semicircle is 19.25 cm² and the perimeter of the given semicircle is 18 cm