12. Use a trigonometric ratio to find the measure of O in the triangle below. Give your answer to the nearest degree.
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Given :-
To Find :-
Solution :-
At angle theta , 9cm side will be considered as the perpendicular and 10cm side will be hypotenuse . So , as we know that ;
[tex]\longrightarrow sin\theta =\dfrac{perpendicular}{hypotenuse}[/tex]
Substituting the respective values,
[tex]\longrightarrow sin\theta =\dfrac{9cm}{10cm}[/tex]
Simplify,
[tex]\longrightarrow sin\theta= 0.9 [/tex]
Take arcsin both sides ,
[tex]\longrightarrow \theta =sin^{-1}(0.9)[/tex]
[tex]\\\longrightarrow\underline{\underline{\theta = 64.15^o }} [/tex]
Hence the required answer is 64.15° .