Please find the surface area!

Ben is three times as old as samantha, who is two years older than half of michel's age. if michel is 12. how old is ben?

Kayla wants to find the width, ab, of a river. she walks along the edge of the river 65 ft and marks point c. then she walks 25 ft further and marks point d. she turns 90° and walks until her location, point a, and point c are collinear. she marks point e at this location, as shown. (a) can kayla conclude that δ and δ are similar? why or why not? (b) suppose de = 15 ft. what can kayla conclude about the width of the river?

If y varies directly as x2 and y=6 when x=6, find the constant of variation.