Answer:
A. On the first day, 3 leaves fall.
B. D. The number of leaves that fall on a given day is 2 times the number of leaves that fell on the previous day.
Step-by-step explanation:
Given

Solving (a) The meaning of 3.
3 represents the initial number of leaves (i.e. the first day) and this proved as follows.
On the first day, n = 0.
Substitute 0 for n in 



Solving (b) The meaning of 2.
2 represents the rate which leaves fall down.
In (a)

Take n = 1
Substitute 1 for n in 



When f(1) is divided by f(0), the result 2. So, the number of leaves doubles everyday
Assume that
a and b = the two legs of the right triangle.
c = the hypotenuse.
The area of the right triangle is 750 yd², therefore
(1/2)*a*b = 750
ab = 1500 (1)
The perimeter is 150yd, therefore
a + b + c = 150 (2)
Let the side fenced with wood be a, at $5/yd. Sides b and c are fenced with steel at $10/y. The total cost is $1200, therefore
5a + 10b + 10c = 1200
or
a + 2b + 2c = 240 (3)
From (2), obtain
c = 150 - a - b (4)
Substitute (4) into (3)
a + 2b + 2(150 - a - b) = 240
-a + 300 = 240
a = 60
From (1), obtain
60b = 1500
b = 25
From (4), obtain
c = 150 - 60 - 25 = 65
Answer:
A. The length of the leg fenced with wood is 60 yd.
B. The length of the leg fenced with steel is 25 yd.

There is one solution to this system of equations. The answer is B.
The answer would be the second option, 13.0 cm.
To find the missing length of the leg, you would use the pythagorean theorem and substitute your inputs in.
a^2+b^2=c^2
11^2+b^2=17^2
121+b^2=289
b^2=168
b=12.96
b=13.0 cm (rounded up)
Yes it would be a triangular prism