As the pen is a triangle, the third side can either be the hypotenuse or a regular side. If the third side is the hypotenuse, it's length would be

feet. If the third side is a regular side, than it would be

≈12.689 feet. This means your third side can either be 17 feet long or 12.689 feet long.
Answer:
D
Step-by-step explanation:$400x.30=$120
400-120=280
$280x.10=28
280-28=252
The formula for arithmetic sequence is given by:
an=a+(n-1)d
where:
an=nth term
a=first term
n=number of terms
thus our first term will be:
a1=8
a2=8+(2-1)(-6)=2
a3=8+(3-1)(-6)=-4
a4=8+(4-1)(-6)=-10
a5=8+(5-1)(-6)=-16
a5=-16
thus the sequence will be:
8,2,-4,-10,-16...
There is a theorem that states that RT =2TH.
3x - 7 = 2(x + 1)
3x - 7 = 2x + 2
x - 7 = 2
x = 9