Cheatography

# Geometry- Circles, Arcs, and Diameters Cheat Sheet by Corinna-Lyons

this is a cheat sheet for the annoying circles and stuff

### equations

 Diameter D = 2 × r Circum­ference C = 2 × π × r Area A = π × r2

### terms

 radius the distance from the center of the circle to its outer rim chord a line segment whose endpoints are on a circle diameter a chord that passes through the center of the circle. the length of the diameter is two times the length of the radius secant a line that intersects a circle in two points tangent a line that intersects a circle in exactly one point point of tangency the point where the tangent touches the circle

### graphing circles

 (x-h)2­+(y­-k)2=r2 h=the x axis, k= the y axis, and r =the radius example: (x-1)2 + (y+3) 2 =4 radius=2 center­=(1,-3)

### arcs- the basic

 major arcs arcs above 180 minor arcs arcs below 180 semicircle arc equivalent to 180

### other sources

 arcs https:­//w­ww.k­ha­nac­ade­my.o­rg­/ma­th/­geo­met­ry/­hs-­geo­-ci­rcl­es/­hs-­geo­-ar­c-m­eas­ure­s/v­/in­tro­-ar­c-m­easure chords https:­//w­ww.y­ou­tub­e.c­om/­wat­ch?­v=m­gKb­pTtDxSk circles overview https:­//w­ww.k­ha­nac­ade­my.o­rg­/ma­th/­geo­met­ry-­hom­e/c­c-g­eom­etr­y-c­ircles good luck friend:) you got this
I believe in you!!!