A triangle has corners at (1,1), (7,9), and (4,2). What is the area of the triangle's circumscribed circle?

1 Answer
Jun 2, 2017

Area of triangle's circumscribed circle is 143.0

Explanation:

Vertices of triangle are A(1,1),B(7,9),(4,2)
Side AB=a=(17)2+(19)2=10.0
Side BC=b=(74)2+(92)2=7.6
Side CA=c=(41)2+(21)2=3.16

Semi perimeter of triangle S=10.0+7.6+3.162=10.38

Area of the triangle At=s(sa)(sb)(sc)
=10.38(10.3810.0)(10.387.6)(10.383.16)=79.17=8.9

Circumscribed circle radius is R=abc4.At
R=10.07.63.1648.9=6.74

Area of circumscribed circle is Ac=πR2=π6.742=143.0