What is the perimeter of the following composite figure?

21 yd

42 yd

47.13 yd

35.13 yd

Question

What is the perimeter of the following composite figure?





21 yd

42 yd

47.13 yd

35.13 yd

anonymous · Answer

attachment

anonymous · Answer

12+9+12+pi*4.5=47.137

anonymous · Answer

How do you find the area?

johnweldon1993 · Answer

First remember (perimeter of circle = circumference)

$$\large C = 2\pi r$$

anonymous · Answer

What confuses me is , how to find the radius

johnweldon1993 · Answer

We know that we have a rectangle with perimeter

$$\large 12 + 9 + 12 + 9 = 42$$

And as we can see...the semicircle has a diameter of 9 (because that is the side of the rectangle) so the radius would be half that...4.5

johnweldon1993 · Answer

So we have

$$\large 42 + \frac{2\pi r}{2} \rightarrow 42 + 4.5\pi = ?$$

anonymous · Answer

perimeter mean total length of outer profile of the figure
12 and 9 are side of the rectangle but another half circle is there so , you have to half the perimeter of the circle , then sum all then you got 47.13.

johnweldon1993 · Answer

Oh, the radius can be seen as

|dw:1405367178259:dw|

so that is the diameter of the semicircle...meaning the radius is half that side

make sense now @Bookreader15