Respuesta :

first fnd SA then times 3/4

SA of sphere=4pir^2
r=13
SA=4pi13^2
SA=4pi169
SA=676pi

times 3/4
SA=507pi

answer is 507pi  squaer units

(if they want to evaluate or aprox, use 3.14 for pi and multiply 507 and 3.14)