The horizontal distance between the origin and the final destination of a projectile is referred to as the range of the projectile. This can be calculated through the equation,
R = v₀²sin2θ / g
where R is the range, v₀ is the initial velocity, θ is the angle and g is the acceleration due to gravity.
Substituting the known values from the given above,
7 = (12 m/s)²(sin2θ) / 9.8 m/s²
The value of θ from the equation is 14.22°.