A circle has a radius of 10 feet and a central angle AOB that measures 180°. What is the area of sector AOB? Use 3.14 for pi and round your answer to the nearest whole number.

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2 Answers
Jun 28, 2018

#157" feet"^2#

Explanation:

#"the area of the sector AOB is calculated as"#

#•color(white)(x)"area of circle"xx"fraction of circle"#

#=pir^2xx180/360#

#=pixx100xx1/2=50pi~~157" feet"^2#

Jun 28, 2018

#157# square feet.

Explanation:

Well, if the central angle #/_AOB=180^@#, and so we can conclude that sector #AOB# is basically a semicircle, where #AB# is the diameter of the circle and #O# is the center.

So, the area of sector #AOB# will be:

#A=1/2pir^2#

We got: #pi=3.14,r=10 \ "ft"#.

#:.A=1/2*3.14*(10 \ "ft")^2#

#=1.57*100 \ "ft"^2#

#=157 \ "ft"^2#