Answer:
Step-by-step explanation:
Triangle BCD is a right angle triangle.
From the given right angle triangle
BC represents the hypotenuse of the right angle triangle.
Taking 45 degrees as the reference angle,
BC represents the adjacent side of the right angle triangle.
BD represents the opposite side of the right angle triangle.
To determine BC, we would apply trigonometric ratio
Cos θ = adjacent side/hypotenuse side. Therefore,
Cos 45 = BC/2√2
√2/2 = BC/2√2
BC = 2√2 × √2/2
BC = 2
