Answer:
Step-by-step explanation:
Based off of what we do know, if we can find length DB we can use the pythagorous theorem (I will be assigning the variable z)
First equation is for triangle ABD
Second is for BCD
And the last one is for ACD
Substitute 
and 
As discovered before
This is a proportion problem. Let the monument me x feet tall.
40/x=5/6
Cross multiply:
240=5x
x=48 ft.
So the monument is 48 ft tall,
Answer:
8/45
Step-by-step explanation:
Write 4 5/8 as an improper fraction: 45/8.
Then invert this result, obtaining:
. This is the "reciprocal" of 4 5/8.
Let the speed of the current equal c
and the speed of the boat in still water equal b.
b + c = 1.5 (b - c)
b + c = 1.5b - 1.5c
0.5b = 2.5c
b = 5c
The speed of the current is 1.5 mph so
b = 5 * 1.5 = 7.5 mph
