Answer:
The length is 15 yards
Step-by-step explanation:
Given
Represent the width with W and length with L: So


Required
Determine the length of the rectangle:
Area is calculated as thus:

Substitute 3W - 12 for L and 135 for Area


Reorder:

Divide through by 3

Expand:



or 
or 
But width can't be negative
So:

Recall that: 


<em>Hence, the length 15 yards</em>
Answer:
one side = 
Step-by-step explanation:
if you draw an octagon on a piece of paper, you can draw a square around it, you should be able to see a diagram of this attached, ignore the 6.
Let's say TP = a
since it's a regular octagon, TP = HT
and using the Pythagoras Theorem, we know a² + b² = c² and thus:
√(AT² + HA²) = HT
and since AT = HA which we will call x, the equation becomes:
√(2x²) = HT = a
rearrange the equation to solve for x and you get:
2x² = a²
x² = 
x =
which, if you rationalise the denominator, you get:
x = 
The answer is 7.
6/4 = 3/2
(3/2) / (3/14) = (3*14)/(2*3) = 42/6 = 7