Find the two possible values of the included angle of a triangle with: sides of length 5 cm and 8 cm, and area 15 cm^2
Take the 8 cm side a the base, and let h be the height.
(1/2)*8*h = 15
h = 15/4 cm
sinA = h/5 where A is the included angle. sinA = 3/4
A = sin-1(3/4) or A ≈ 48.6 degrees
Alternatively A ≈ (180 - 48.6) degrees → 131.4 degrees
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