Question

a square figure with side 4 ft has a semicircle with radius 2ft at the top what is the perimeter of the figure ? what formula should be used ?​

Answer 1

Answer:

~18.28 ft. / 12 + 2π ft. (Read explanation please!)

Step-by-step explanation:

I) Find the square's perimeter:

Obviously, a square's perimeter is its side length x 4. However, there would be a semicircle on top of it. So, to find it we use:

4 x 3 = 16 ft. (Since 1 of the sides is covered by the semicircle)

II) Find the semicircle's perimeter:

Finding the semicircle's perimeter is a bit more complicated, but no worries! We can use this formula:

πr + 2r (pi x radius + radius x 2)

But WAIT: We need to make sure we remove that one side of the square we mentioned earlier. So we would use:

πr (pi x radius)

In terms of π, the perimeter would be:

2π = 2π ft.

Or, if you used a standard approximation of π, let's say 3.14, it would be:

2(3.14) = ~6.28 ft.

III) Add them up:

If we wanted to state the total perimeter using 3.14 as π, we would say the formula is:

2(3.14) + 4(3) = 18.28 ft.

Or in terms of π:

2π + 4(3) = 12 + 2π ft.