posted by c .
A rectangle is 80 cm long and 20 cm wide. Find, to the nearest degree, the acute angle formed at the intersection of the diagonals.
take one of the right-angled triangles, call the base angle Ø
tanØ = 20/80 = 1/4
Ø = appr. 14.04°
can you take it from there?
I see pairs of isosceles triangles !