Finally they share the same angle which are AOC and AOB. Lets extend
the line OC in a vertical direction, and set a point D. We know that the
central angle of the sector, AOB, is 143.5°. We also know that the sector
is vertically symmetrical, so as a result, the line CD bisects angle AOB.
AOD and BOD are both half of AOB which is 71.75°. AOC and AOB
must be a supplementary angle of 71.75°, which is 108.25°.
Image 3-13: Diagram of Infield of a Baseball Field VII
(Not Drawn to Scale)Since we have proven that two triangles have two sides with same lengths
and same angle between them, we can know that these triangles have a