Answer:
D. 24 degree
Step-by-step explanation:
Sides of the triangle are
a = 330 ft
b = 180 ft
c = 420 ft
From cosine rule we have
[tex]\angle A=\cos^{-1}(\dfrac{b^2+c^2-a^2}{2bc})\\ =\cos^{-1}(\dfrac{180^2+420^2-330^2}{2\times180\times 420})\\ =48.65^{\circ}[/tex]
[tex]\angle B=\cos^{-1}(\dfrac{a^2+c^2-b^2}{2ac})\\ =\cos^{-1}(\dfrac{330^2+420^2-180^2}{2\times 330\times 420})\\ =24.17^{\circ}[/tex]
[tex]\angle C=\cos^{-1}(\dfrac{a^2+b^2-c^2}{2ab})\\ =\cos^{-1}(\dfrac{330^2+180^2-420^2}{2\times 330\times 180})\\ =107.19^{\circ}[/tex]
The smallest angle in the triangle is [tex]\angle B=24.17^{\circ}[/tex].