Explanation: here we may assume a linear relationship.
Where S, the shadow, is equivalent to H, the height.
and the relation is S = K*H
where K is a constant.
So if a person 6 feet tall casts a 4-foot shadow, we have:
4 = K*6
now we need to isolate K by dividing both sides by 6.
K = 4/6 = 2/3
Now that we know the value of K, if we want to find the shadow casted by a 21 ft tree, we need to solve:
S = (2/3)*21 = 2*(21/3) = 2*7 = 14
So the shadow casted is of 14ft
a (congress) should be your answer since they make all federal laws in the u.s.