Iwould be much appreciated if somebody took time out of their day to answer this for me.

Problem 4
You have to assume something or it is unsolvable.
We will assume that the triangle is divided into 2 smaller right triangles. They will be subject to a^2 + b^2 = c^2
a = 32/2 = 16
b = h
c = 20
20^2 = 16^2 + h^2
400 = 256 + h^2 Subtract 256
400 - 256 = h^2
144 = h^2
h = sqrt(144)
h = 12

Now we can find the area.
h = 12
base = b = 32

Area = 1/2 * b * h
Area = 1/2 * 32 * 12
Area = 192 square inches.

Problem 5
Same assumption. Same method.
a^2 + b^2 = c^2
c = 25
b = 7
h = ???
h^2 + 7^2 = 25^2
h^2 + 49 = 625
h^2 = 625 - 49
h^2  = 576
h = sqrt(576) 
h = 24

Area = 1/2 Base * h
base = 2*7
base = b = 14

Area = 1/2 * 14 * 24
Area = 168 <<<< answer.

Num of plants = (original#ofplants)*(1.6)^t

Um what? rephrase that ?