Trigonometry: what is the angle of tan theta, if the opposite side = 0.5 and the adjacent side = 1.5?

Question

For a right angled triangle?

Answer 1

press "shift" (or "2nd function") then press tan then (0.5/1.5)

Include the brackets and you will get the answer

You could use the calculator on the computer but to do that first do 0.5 / 1.5

then click the "inverse" button

then click tan

in degrees the answer is 18.43 (2dp)

in radians the answer is 0.32 (2dp)

Answer 2

tan(theta)=.5/1.5

tan(theta)=5/15

tan(theta)=1/3

theta=arctan(1/3)

theta=.32175 radians or 18.435 degrees