A circle has a diameter with endpoints $( - 2,1 )$ and $( 18,17 )$. Find the coordinates of the center.
A) $( 16,18 )$
B) $( - 12 , - 7 )$
C) $( 8,9 )$
D) $( 38,33 )$

Question

Quizplus · Accepted Answer

The center of a circle is the midpoint of its diameter. The midpoint formula is $\frac{x_1 + x_2}{2}, \frac{y_1 + y_2}{2}$. Applying this to the given points $(-2,1)$ and $(18,17)$, we get the center as $(\frac{-2 + 18}{2}, \frac{1 + 17}{2}) = (8, 9)$.

A Circle Has a Diameter with Endpoints (−2,1)( - 2,1 )(−2,1)

A Circle Has a Diameter with Endpoints $( - 2,1 )$