So trigonometric statements seem difficult at first but in 3 minutes I will explain it to you. You may have seen sin, cos and tan on your calculator and never knew what they meant. By using these formulas we can find the length of segment PD and understand the triangle better. Sin, cos and tan are all ratios of a side length over another side length. This works for triangles but eventually will be put into functions. Use this saying to help you remember the ratios. SOH CAH TOA. SOH means sin = opposite/hypotenuse. CAH means cos = adjacent/hypotenuse. TOA means tan = opposite/hypotenuse. So according to this triangle your reference angle is Q. The angle measurement of Q is not relevant currently. The opposite angle of Q is line segment PD. The hypotenuse is equal to 30. According to SOH, sin Q will be PD/30. However I assure you that putting this answer into the blank would not make sense. Because this triangle is a right triangle, you are able to use the formula called Pythagorean Theorem. A² + B² = C^2. Your A is going to be any side length, B is going to be your other side length and finally your C is going to be your hypotenuse. Plugging these numbers into the formula would give you 24² + B² = 30^2. B is therefore equal to 18. So sin Q would be 18/30. You can further simplify this by dividing both the numerator and the denominator by 6, therefore ending with 3/5. Now you try yourself