Math Circle Stuff

Two chords intersect (finding angle)

average the arcs

Two chords intersecting (finding chord)

Take “sides”, multiply and set equal

Central angle

EQUAL TO ARC

The one that’s not central but kinda far away still inside circle

HALF THE ARC

Tangent and Chord

HALF THE ARC

Angle where it’s sticking out like a cone (angle)

Big arc minus little arc divided by 2 OR ½ (Big Arc—Little arc) = angle

2 secants drawn from exterior point (chord)

Whole thing x Outer thing = Other whole thing x Other outer bit

Tangent and Secant

Whole thing x Outer thing = Tangent measure squared

Radii and Tangents (what do you know?)

PERPENDICULAR!!!!!

What do all circles have in common?

ARCS ADD TO 360 DEGREES AND ALL RADII ARE EQUAL. EVERYTIME!!!!!