Answer:
cosine rule - cos = 
Step-by-step explanation:
Here the ladder is acting as hypotenuse and base as adjacent.
Formula: cosθ = 
If the chalkboard is just rectangular we can just use:
(2 x L) + (2 x W)
or
L+L+W+W
L= Length
W= Width
Answer:
A) 

Step-by-step explanation:
When given a balanced scale (represented by a hanger in this image), the sum of the values on one side equals the value on the other side. Thus, the equation that this hanger represents is the following:

Use inverse operations to solve this equation,



Answer:
.39 cents
Step-by-step explanation:
1.56 divided by 4 is .39
Answer:
A=lw+l(w
2)2+h2+w(l
2)2+h2
Step-by-step explanation: