Posted by Shane on Sunday, March 3, 2013 at 3:04am.
A rectangle has sides 170mm and 130mm.What is the angle between the diagonals?

maths  Damon, Sunday, March 3, 2013 at 3:13am
look at triangle of altitude (13/2) = 6.5 and base (17/2) = 8.5
x = half of angle between diagonals.
tan x = 8.5/6.5
x = 52.6
2x = big angle between diagonals = 105.3 degrees
small angle between diagonals = 180  105.3 = 74.8 degrees