In a right triangle, the opposite leg at θ is 4cm and its adjacent leg is 8cm. Find the acute angle θ in degrees, to one decimal place. Use inverse tangent on a calculator.
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Answer: 26.6
tanθ=84.
θ=tan−1(84)≈26.6∘. Set the calculator to degrees.
Example 2
In a right triangle, the opposite leg at θ is 6cm and the hypotenuse is √117cm. Find the acute angle θ in degrees, to one decimal place. Use inverse sine on a calculator.
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Answer: 33.7
sinθ=√1176.
θ=sin−1(√1176)≈33.7∘. Set the calculator to degrees.
Example 3
In a right triangle, the adjacent leg at θ is 8cm and the hypotenuse is √128cm. Find the acute angle θ in degrees, to one decimal place. Use inverse cosine on a calculator.
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Answer: 45
cosθ=√1288.
θ=cos−1(√1288)≈45∘. Set the calculator to degrees.
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