2 sentences

1. 这两条直线在圆心相交。

   zhè liǎng tiáo zhí​xiàn zài yuán​xīn xiāng jiāo.

   These two lines intersect at the center of the circle.

   Source: Dong Chinese Dictionary

2. 这两条直线在圆心处相交。

   zhè liǎng tiáo zhí​xiàn zài yuán​xīn chù xiāng​jiāo.

   These two straight lines intersect at the center of the circle.

   Source: Dong Chinese Dictionary