Answer: a = 15
Step-by-step explanation:
From the given right angle triangle
AB represents the hypotenuse of the right angle triangle.
With 51 degrees as the reference angle,
BC represents the adjacent side of the right angle triangle.
AC represents the opposite side of the right angle triangle.
To determine a = BC, we would apply trigonometric ratio
Cos θ = adjacent side/hypotenuse side. Therefore,
Cos 51 = a/23.5
0.6293 = a/23.5
a = 0.6293 × 23.5 = 14.79
Approximating to the nearest whole number, it becomes 15
