Trig Reference

Unit Circle Reference

Click any standard angle on the unit circle to inspect the exact coordinate, radians, degrees, and the matching sine, cosine, and tangent values. This is built to work as a quick lookup sheet and a study guide at the same time.

Standard angles only Focuses on the angles most students actually memorize and use: 0°, 30°, 45°, 60°, and their quadrant reflections.

Exact and decimal values See the symbolic form first, then the decimal approximation underneath for fast checking.

Clickable study flow Use the circle itself, quick angle buttons, or the table to move through values without losing context.

Interactive Circle

Pick an angle below or click a point on the SVG. The selected angle is highlighted in the circle and the table.

Angle	Coordinates	sin	cos	tan

Selected Angle

Exact values always appear first. Decimal approximations are included underneath for calculator checks.

Angle

45°

π/4 radians

Coordinates

(√2/2, √2/2)

(0.7071, 0.7071)

sin θ

√2/2

0.7071

cos θ

√2/2

0.7071

tan θ

1.0000

Quadrant

Quadrant I

All trig values are positive here.

Coordinate pattern The core first-quadrant coordinates repeat as `(√3/2, 1/2)`, `(√2/2, √2/2)`, and `(1/2, √3/2)`, then signs change by quadrant.

ASTC sign rule Quadrant I: all positive. Quadrant II: sine positive. Quadrant III: tangent positive. Quadrant IV: cosine positive.

Tangent reminder `tan θ = sin θ / cos θ`, so tangent is undefined when cosine equals 0 (90° and 270°).