Answer:
D. 75 ft
Step-by-step explanation:
Line DE parallel to line CB makes triangle ADE similar to triangle ACB. This means corresponding sides are proportional:
DE/AD = CB/AC
DE = AD×CB/AC = (70 ft)×(225 ft)/(70 ft +140 ft) = (225 ft)/3
DE = 75 ft
The distance across the lake is 75 feet.
