An isosceles triangle has legs 4 feet long. If the vertex angle measures 30 degrees, find the length of the base.

1 answer

let the base be 2x
Construct an altiude to the base, resulting in a right-angled triangle with hypotenuse 4, angle 15° and opposite side x
sin15 = x/4
x = 4sin15
so the base is 2x, or 8sin15°

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