Answer: 127.1 cm
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Explanation:
Divide the figure so we have a semicircle on the left and a rectangle on the right. The rectangle is 30 by 25. The semicircle has diameter 30.
If we consider a full circle of diameter 30, then its circumference is exactly C = pi*d = pi*30 = 30pi centimeters.
But we only have half a circle, so we cut that in half to get 30pi/2 = 15pi. That's the distance around the curved portion of this diagram. The straight line portions are handled as exactly as you expect.
Add up the distances around the outer edges to get:
15pi+25+30+25 = 15pi+80
The exact perimeter, in terms of pi, is 15pi+80 centimeters.
To get an approximation of this, we can use pi = 3.14 to get
15*pi + 80 = 15*3.14+80 = 127.1 cm
To get a better approximation, use more decimal digits in pi. Or you can let your calculator handle the decimal digits of pi (in other words, use the stored version of it).
