Answer
The length of the side opposite the 40-degree angle is 6.43cm.
Work Step by Step
The first step is to denote the side opposite the 40-degree angle as "x" and to use the given length, 10cm, as the hypotenuse. We can use the sine rule of $\frac{opposite}{hypotenuse}$ to find the missing length in question.
This would be written as $sin 40 = \frac{x}{10}$.
The next step is to multiply both sides by 10 to isolate x. We can then solve for sin 40 and multiply by 10 to get the value of 6.43.
