Which equation could be used to find the value of x? Triangle DEF where angle E is a right angle. DE measures x. DF measures 55. Angle D measures 49 degrees.

cos 49° = x over 55
cos 49° = 55 over x
sin 49° = x over 55
sin 49° = 55 over x

The equation that can be used to find x is cos 49° = x /55

Triangle DEF :

The following trigonometric rations can be used to find x. Therefore,

cos ∅ = adjacent / hypotenuse

adjacent side = x

hypotenuse = 55

Therefore,

cos 49° = x / 55

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cos 49° = x over 55

Step-by-step explanation:

In trigonometry, Formula of sine and cosine :

By using the given description we draw the follwoing figure ( given in attachment).

Hypotenuse DF = 55 [Side opposite to right angle]

Side opposite to

Side adjacent to

So ,

Hence, the correct answer is cos 49° = x over 55.