{{TProblem | A horizontal curve with a 1200 radius is to design for two perpendicular with PI station at 20 chainage. their are 12 width lane 10 feet shoulder and a design friction factor of 0.65. calculate the following ‹a› tangent distance ‹b› external distance ‹c› length of the middle ordinate ‹d› length of curve ‹e› PC station ‹f› PT station