Right Triangle Trigonometry: 30-60-90 and Sine/Cosine Methods

Notes

```svg <svg width="400" height="300" xmlns="http://www.w3.org/2000/svg"> <line x1="50" y1="250" x2="350" y2="250" stroke="black" stroke-width="2"/> <line x1="50" y1="250" x2="50" y2="50" stroke="black" stroke-width="2"/> <line x1="50" y1="50" x2="350" y2="250" stroke="black" stroke-width="2"/> <text x="200" y="140" font-family="Arial" font-size="20" fill="black">20</text> <text x="30" y="150" font-family="Arial" font-size="20" fill="black">b</text> <text x="200" y="270" font-family="Arial" font-size="20" fill="black">a</text> <text x="320" y="240" font-family="Arial" font-size="20" fill="black">30°</text> <rect x="50" y="230" width="20" height="20" fill="none" stroke="black" stroke-width="2"/> </svg> ``` 1) Remember that this is a common 30,60,90 right triangle. ``` Noteworthy! NOTES: Use Trig to Find Missing Sides Find the missing sides (a and b): METHOD 1 When the angles are 30,60,90 there is a shortcut for calculating the missing sides. 20 b 30° a To solve for b (shortest side): divide the hypotenuse by 2 → 20 / 2 = 10 so b=10. To solve for a (the longer missing side): multiply the hypotenuse by √3/2 → 20 x √3 = 10√3 1 2 ``` NOTES: Use Trig to Find Missing Si...