Complex sentence: Have Dash II was designed with a composite body, trapezodial in shape, intended both to reduce radar-cross-section and to resist heat at hypersonic speeds, the missile being intended to operate at Mach 5.
Split into simpler sentences: Have Dash II was designed with a composite body, trapezodial in shape. This was intended both to reduce the missle's radar-cross-section and to resist heat at hypersonic speeds, as the missile was intended to operate at Mach 5.