For angles of projection of a projectile at angles (45°θ) and (45° +-θ), the horizontal ranges described by the projectile are in the ratio of :

1 : 1 2 : 3 1 : 2 3 : 2

1 : 1

The range will the same for complementary angles. \(\frac{R_1}{R_2} = \frac{[\frac{u^2sin2(45-\theta)}{g}]}{[\frac{u^2sin2(45+\theta)}{g}]} = \frac{u^2sin(90-2\theta)}{u^2sin(90+2\theta)} = \frac{cos2\theta}{cos2\theta} = 1\)