# Brandon launches a projectile at an angle of 75° above the horizontal, which strikes the ground a certain distance down range. For what other angle of launch at the same speed would the projectile land just as far away?

Nov 28, 2015

${15}^{\circ}$

#### Explanation:

Complementary launch angles give the same range under the same conditions.

This means the two angles must add up to ${90}^{\circ}$.

So $90 - 75 = {15}^{\circ}$

The maximum range is when the launch angle is ${45}^{\circ}$.