Answer : d. 438.5 ft
The diagram for the given statement is attached below.
Two sides AB and AC are equal so the angle B = angle C
WE know sum of three sides of a triangle = 180
angle A + angle B + angle C = 180
55 + B + C = 180
B + C = 180 -55 = 125
B and C are equal so we divide 125 by 2
angle B = 62.5 and angle C = 62.5
Now we apply sin law
[tex] \frac{sin A}{a} = \frac{sin B}{b} [/tex]
[tex] \frac{sin 55}{a} = \frac{sin 62.5}{150} [/tex]
150 * sin(55) = sin(62.5) * a
122.8728066 = sin(62.5) * a
a = [tex] \frac{ 122.8728066}{sin(62.5)} [/tex]
a= 138.52 feet
To find perimeter we add all the sides
150 + 150 + 138.52 = 438.52 feet