puts "======================="
puts "BUC60607"
puts "It takes visual check for this BUC"
puts "======================="

set len_ch 2513

point p 1600 300
line l 0 500 2000 500
cirtang c p l 400
checklength c_1 -l 2513.2741228718346
checklength c_2 -l 2513.2741228718346