Answer:
Step-by-step explanation:
BD is opposite the 30° angle. The sine of 30° is 0.5. The sin of an angle in a right triangle is opposite/hypotenuse so BD = sin 30°x8.
Now you have two known lengths The third can be found by applying the Pythagorean theorem: BC²+BD²=CD², from which you can establish a numerical value for BC.