Posted by RSSnews (#1) 1210 days ago (http://feedproxy.google.com)
Figure skating champion Kim Yu-na is pictured in a math textbook for U.S. high school students. She appears in the part introducing trigonometry. In the U.S., math textbooks commonly feature photos of sports stars' performances to explain geometry.
The textbook published by Houghton Mifflin Harcourt features Kim twice, presenting the following problems: calculate the angle created by a figure s