Answer:
The correct answer is option 1.
Step-by-step explanation:
Height of the wall = p = 9 ft (Perpendicular)
length of the of the base of the wall = b = 12 ft (Base)
Length of the diagonal brace = h = ?(Hypotenuse)
Applying Pythagoras theorem ;
[tex](Hypotenuse)^2=(Perpendicular)^2+(Base)^2[/tex]
[tex](Hypotenuse)^2=(9 ft)^2+(12 ft)^281 ft^2+144 ft^2[/tex]
[tex](Hypotenuse)=\sqrt{225 ft^2}=15 ft[/tex]
15 feet is the length of a diagonal brace.
