Answer :

Answer:

B

Step-by-step explanation:

Using the cosine ratio in the right triangle

cos20° = [tex]\frac{adjacent}{hypotenuse}[/tex] = [tex]\frac{4}{x}[/tex] ( multiply both sides by x )

x × cos20° = 4 ( divide both sides by cos20° )

x = [tex]\frac{4}{cos20}[/tex] ≈ 4.26 ( to the nearest hundredth )

semsee45

Answer:

B. cosine

Step-by-step explanation:

In the given right triangle, one of the acute angles measures 20°. The adjacent leg to this angle measures 4 units, and the hypotenuse is labelled  'x'.

To solve for x, we use the cosine function, as the cosine trigonometric ratio in a right triangle is defined as the ratio of the length of the adjacent side to the hypotenuse of the given angle.

[tex]\cos \theta=\dfrac{\textsf{Adjacent side}}{\textsf{Hypotenuse}}\\\\\\\cos 20^{\circ}=\dfrac{4}{x}\\\\\\x=\dfrac{4}{\cos 20^{\circ}} \\\\\\ x=4.26\; \sf (2\;d.p.)[/tex]

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