Weaver Matte

mathematical problem help!!!?

1.a protractor is in the shape of a semi-circle of radius 5cm.calculate the area of the protractor.(use the value 3.14)pls show the working.
2.the floor of a round house is 10m in diameter.a weaver charges $15 500 to make a mat to fit the floor.find the cost of the mat per square metere.(use value3.1 for pi~.)pls show working

1) Area of circle = pi * r^2

Therefore, area of semicircle = pi * r^2 / 2

Area of protractor = 3.14 * 5 * 5 / 2 = 39.25 cm^2

2)Diameter = 10 m, hence radius = 5 m

Area of floor = pi * r^2 = 3.14 * 5 * 5 = 78.5 m^2

Now, total cost = $ 15500

Total area = 78.5 m^2

Cost per m^2 = 15500 / 78.5 = $ 197.45

Hope it helps !

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