Respuesta :
Answer: He needs 20 minutes to install all of the fence.
Step-by-step explanation:
Since we have given that
Dimensions of triangle he has to use for fencing are
15 feet, 8 feet, and 20 feet.
1) For making it a right triangle it must satisfy the "Pythagorus theorem" which states that
[tex]H^2=B^2+P^2\\\\20^2=15^+8^2\\\\400\neq 225+64\\\\400\neq 289[/tex]
No, it will not be able to make a right triangle.
2) Joel cut the longest piece of wood in order to make a right triangle.
So, from above we get that
[tex]\sqrt{289}=17\ feet[/tex]
So, Longest side must be 17 feet.
It is takes him 30 seconds to install each foot of fencing,
Total perimeter of fencing will be
[tex]17+15+8=40\ feet[/tex]
So, for 1 foot he needs = 30 seconds
For 40 feet , he will need
[tex]40\times 30=1200\ seconds\\\\\frac{1200}{60}=20\ minutes[/tex]
Hence, he needs 20 minutes to install all of the fence.