7. (20 points) A horizontal curve with 5°25'36" degree of curvature has a central angle of 38°and the P.C. at station 23+00.00. a. Determine the radius; b. Determine the length

of external distance; c. Determine the P.T. station; d. Estimate the available stopping sight distance at thiscurve if there is a house located 60 ft from the centerof the curve, as noted in the figure; Re. If the curve runs level terrain with a design speed of 60mph, determine if the stopping sight distance is adequate.