Work out the perimeter of a semicircle with radius 7 cm.
Give your answer in terms of л.
7 cm
Optional working
Ansv
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Answer :

To find the perimeter of a semicircle with a radius of 7 cm, we need to follow these steps:

1. Understand the components of the perimeter:
- The perimeter of a semicircle is made up of half the circumference of the full circle plus the diameter of the circle.

2. Calculate the circumference of the full circle:
- The formula for the circumference of a full circle is [tex]\(2 \pi r\)[/tex], where [tex]\(r\)[/tex] is the radius.

For a circle with radius 7 cm:
[tex]\[ \text{Circumference} = 2 \pi \times 7 = 14 \pi \][/tex]

3. Calculate half of the circumference:
- Since we are dealing with a semicircle, we only need half of the full circumference.

[tex]\[ \text{Half the circumference} = \frac{14 \pi}{2} = 7 \pi \][/tex]

4. Calculate the diameter of the circle:
- The diameter ([tex]\(d\)[/tex]) is twice the radius ([tex]\(r\)[/tex]).

For a circle with radius 7 cm:
[tex]\[ \text{Diameter} = 2 \times 7 = 14 \text{ cm} \][/tex]

5. Add the half circumference and the diameter to get the perimeter of the semicircle:
- The total perimeter of the semicircle is the sum of the half circumference and the diameter.

[tex]\[ \text{Perimeter} = 7 \pi + 14 \][/tex]

Therefore, the perimeter of the semicircle with a radius of 7 cm, in terms of [tex]\(\pi\)[/tex], is:
[tex]\[ \boxed{7 \pi + 14 \text{ cm}} \][/tex]