Respuesta :
Answer:
The amount of fencing needed to surround the perimeter of the flower bed is 40 feet
Step-by-step explanation:
The picture of the question in the attached figure
step 1
Find the length side b
Applying the law of cosines
[tex]c^2=a^2+b^2-2(a)(b)cos(C)[/tex]
where
[tex]c=13\ ft\\a=10\ ft\\C=50^o[/tex]
substitute
[tex]13^2=10^2+b^2-2(10)(b)cos(50^o)[/tex]
solve for b
[tex]169=100+b^2-(20b)cos(50^o)[/tex]
[tex]b^2-[20cos(50^o)]b-69=0[/tex]
[tex]b^2-12.86b-69=0[/tex]
solve the quadratic equation by graphing
The solution is b=16.9 ft
see the attached figure
step 2
Find the perimeter of triangle ABC
[tex]P=AB+BC+AC[/tex]
substitute the given values
[tex]P=13+10+16.9=39.9\ ft[/tex]
Round to the nearest foot
[tex]P=40\ ft[/tex]
therefore
The amount of fencing needed to surround the perimeter of the flower bed is 40 feet

