geometry
posted by shelby .
a rectangle is 80 cm long and 20 cm wide. find, to the nearest degree, the acute angle formed at the intersections of the diagonals.

The diagonal forms a hypotenuse with a length sqrt[80^2 + 20^2] = 82.462
The acute angle formed at the corner is arctan 20/80 = 14.036 degrees. Where the diagonals cross, the acute angle is twice that, or 28.072 degrees. Round that to 28 degrees.