Unit Circle Quiz: Practice Radians, Degrees, and Key Coordinates
Quick unit circle practice test. 20 questions, instant results.
Editorial: Review CompletedUpdated Aug 27, 2025
This unit circle quiz helps you practice radians, degrees, signs, and exact sine and cosine at common angles. Work through 20 quick questions to check what you know and build speed. Want more? Try the unit circle values quiz, drill coordinates with fill in the unit circle, or broaden your skills with an interactive trigonometry quiz.
Study Outcomes
- Understand the definitions and properties of the unit circle.
- Apply the relationships between angles and their corresponding coordinates.
- Calculate sine, cosine, and tangent values for standard angles.
- Analyze the behavior of trigonometric functions across different quadrants.
- Interpret the significance of radian measure on the unit circle.
Unit Circle Quiz: Practice Test Cheat Sheet
- Unit Circle Basics - Imagine a circle of radius 1 centered at the origin; this simple shape is the foundation of all trigonometry. Every point on this circle corresponds to an angle and gives you sine and cosine values in a snap.
- SOH‑CAH‑TOA Mnemonic - Lock in your sine, cosine, and tangent ratios with the classic "SOH‑CAH‑TOA" chant: Sine = Opposite/Hypotenuse, Cosine = Adjacent/Hypotenuse, Tangent = Opposite/Adjacent. This catchy phrase will save you brainpower during crunch time.
- ASTC Quadrant Signs - Use "All Students Take Calculus" to remember sign rules in each quadrant: all positive in I, sine positive in II, tangent positive in III, and cosine positive in IV. This quick trick stops you from second‑guessing signs mid‑problem.
- Key Angle Values - Memorize sin and cos for 0°, 30°, 45°, 60°, and 90° using the pattern sin(θ)=√n/2 and cos(θ)=√(4−n)/2 (n=0,1,2,3,4). This formulaic approach helps you recall exact values without a calculator.
- Left‑Hand Trick - Bend each finger on your left hand to represent 0°, 30°, 45°, 60°, and 90°; the number of fingers below the bend gives sin, and above gives cos (take √finger count/2). This hands‑on hack turns abstract numbers into a fun handshake.
- Beyond Right Triangles - The unit circle extends trig functions to all real angles, not just acute ones in right triangles. Embrace this broader view to solve problems that go past 0° - 90°.
- Coordinates as Cos & Sin - On the unit circle, every point's x‑coordinate equals cos(θ) and y‑coordinate equals sin(θ). This geometric link is your shortcut to visualizing and calculating values.
- Degrees ↔ Radians - Convert like a pro: 180° equals π radians, so multiply or divide by π/180 to switch between units. Mastering this interchange keeps your answers in the right format.
- Reciprocal Functions - Expand your toolkit with csc = 1/sin, sec = 1/cos, and cot = 1/tan. These reciprocals pop up in identities and integrals, so get comfy with them now.
- Trig Identity Mnemonics - Use playful phrases like "Some Old Horses Chew Apples Happily Throughout Old Age" to nail SOH‑CAH‑TOA and other identities. Mnemonics turn dry formulas into memorable jingles.