That is an important theorem in geometry: if two lines intersect to form adjacent congruent angles, then the lines are perpendicular. Those congruent angles would be right angâ¦les.
Williams later became chief surgeon of the Freedmenâs Hospital. Daniel Hale Williams III was born on January 18, 1856, in Hollidaysburg, Pennsylvania, to Sarah Price Williams and Daniel Hale Williams II. The couple had several children, with the elder Daniel H. Williams inheriting a barber business.
Daniel Hale Williams. For other people named Daniel Williams, see Daniel Williams (disambiguation). Daniel Hale Williams (January 18, 1856 â August 4, 1931) was an African American general surgeon, who in 1893 performed the second documented successful pericardium surgery to repair a wound in the United States of America.