Answer:

Step-by-step explanation:
Area = pi*r^2
Area = pi*9^2
Area = 
X miles per hour - <span> speed of the boat in still water
(x - 2) - speed up the river
(x + 2) - speed down the river
</span>

=

30 * (x + 2) = 38 * (x - 2)
30x + 60 = 38x - 76
- 8x = - 136
x =
17 miles per hour - <span>
the speed of the boat in still water.</span>
Answer:
RS=13
Step-by-step explanation:
RS+ST=RT
2w+1+w-1=18
3w=18
w=6
RS= 2w+1= 2(6)+1= 12+1= 13
Option A, it’s the base times the height