Question

What will be the angle of projection of a projectile for which range R and maximum height H are equal

Answer 1

hope it helps
see attachment

Answer 2

Hmax = H
Range = R

H = R
u²sin² Ɵ/2g = u²sin2 Ɵ/g
sin² Ɵ/2 = 2sin Ɵ × cos Ɵ
sin Ɵ = 4cos Ɵ
tan Ɵ = 4
Ɵ = tan^-1(4)
Ɵ = 67.5°