D. 123.0 math question if you get this right i will mark you as a brainliest

What are you given are two sides and the angle in between those sides. Because it's side-angle-side as given left to right, it's called an SAS triangle. When given this combo, we use the L aw of Cosines.

b² = a² + c² - (2ac * cos (B) by the formula for Law of Cosines - remember it as side squared plus side squared minus double the sides and the cosine of the included angle

b² = 65² + 71² - (2 * 71 * 65 * cos (123°)) where we put in our two sides and angle

b² = 4225 + 5041 - (9230 * cos 123°)

b² = 9266 - (9230 * -0.54463903501) by evaluating the cosine of 123 degrees

b² = 9266 - (-5027.01829319)

b² = 9266 + 5027.01829319 by distributing the negative sign outside

b² = 14293.0182932

b = 119.553411

Rounded to one place, b is 119.6 and choice "A" is the right measurement.

b

step-by-step explanation: