which trig function is this? sin cos tan

Explanation:

Step1: Recall trigonometric function definitions

Trigonometric functions in a right - triangle: (\sin\theta=\frac{\text{opposite}}{\text{hypotenuse}}), (\cos\theta=\frac{\text{adjacent}}{\text{hypotenuse}}), (\tan\theta=\frac{\text{opposite}}{\text{adjacent}})

Step2: Identify sides relative to the given angle

For the (20^{\circ}) angle, the side labeled (x) is the opposite side and the side labeled (5) is the adjacent side.

Step3: Match with trigonometric function formula

Since (\tan\theta=\frac{\text{opposite}}{\text{adjacent}}), substituting (\theta = 20^{\circ}), opposite (=x) and adjacent (=5), we use the tangent function.

Answer:

(\tan)