A50 ft tall building casts a shadow 20 yd long. at the same time, niko casts a shadow that is 8 ft long. how tall is niko?

Ijust need these 2 questions answered (the second pic is just confirmation i'm not confident in that answer)

Yvaries directly as x. y =90 when x=6. find y when x=13

Technicians have installed a center pivot, circular irrigator for a farm that covers 25 acres. a.) how long is the irrigation boom (in feet) from the center pivot to its farthest extent? b.) if the irrigation boom makes 4 full revolutions in a day, how many miles does the end of the boom travel in 5 days?