Finding Sides and Angles with Trigonometry
When solving for unknown sides or angles in right triangles, you'll use the three primary trigonometric ratios: sine, cosine, and tangent. These powerful tools connect the angles and sides of any right triangle.
To find a missing side, select the appropriate trig ratio based on what you know. For example, if you know the angle and hypotenuse and need to find the opposite side, use sine. Rearrange the equation to solve for your unknown by multiplying or dividing both sides as needed.
To find a missing angle, you'll need to use the inverse trigonometric functions (sin⁻¹, cos⁻¹, or tan⁻¹). Set up your ratio first, then apply the inverse function to isolate the angle. Remember that your calculator must be in degree mode for these problems!
💡 Quick Tip: Choose your trig ratio by identifying what you know and what you need to find. SOH-CAH-TOA reminds us: Sine = Opposite/Hypotenuse, Cosine = Adjacent/Hypotenuse, Tangent = Opposite/Adjacent.