act math<\/a>. after that, we’ll go right into the skills and definitions needed for the test.<\/p>\nthe formulas themselves are not too difficult to remember. what might trip you up, however, are the vast amount of key terms you are expected to know.<\/p>\n
lastly, since act test makers have a tendency to combine circles, triangles, and other possibe shapes together in one problem, you’ll need to utilize skills from all parts of your geometry toolkit to handle them.<\/p>\n
<\/p>\n
act math: definition of a circle<\/h2>\n a circle is a set of all the points that are equidistant from a point (the center of the circle). you probably already know what a circle looks like, but it’s important to know the formal definition so that you can confidently handle any conceptual problems that come up.<\/p>\n
act math: glossary of circle terms<\/h2>\n radius<\/strong><\/p>\na line drawn from the center of a circle out to the edge of the circle.<\/p>\n
formula: r<\/p>\n
diameter<\/strong><\/p>\na line drawn from one edge of a circle out to the other side of the circle. it goes through the center of the circle, cutting it in half.<\/p>\n
formula: 2r<\/p>\n
circumference<\/strong><\/p>\nthe length of the perimeter of the circle.<\/p>\n
formula: 2*(pi)*r<\/p>\n
area<\/strong><\/p>\nthe size of the enclosed region of a circle.<\/p>\n
formula: (pi)r2<\/sup><\/p>\narc length<\/strong><\/p>\nthe length of a particular fraction of the circumference of a circle.<\/p>\n
formula: (x\/360)*circumference<\/p>\n
x equals the number of degrees of the arc’s central angle.<\/p>\n
minor arc<\/strong><\/p>\nthe shorter distance along a circle between two points on the edge of the circle.<\/p>\n
major arc<\/strong><\/p>\nthe longer distance along a circle between two points on the edge of the circle.<\/p>\n
sector<\/strong><\/p>\nthe area of a circle enclosed by an arc and two radii.<\/p>\n
formula: (n\/360)*(area)<\/p>\n
n is the degree measure of the central angle of the sector.<\/p>\n
concentric circles<\/strong><\/p>\ncircles that have the same center and are of a different size.<\/p>\n
semicircle<\/strong><\/p>\nhalf of a circle is called a semicircle.<\/p>\n
chord<\/strong><\/p>\na line that goes from one edge of the circle to the other side. unlike the diameter, chords don’t necessarily have to go through the center.<\/p>\n
a diameter is a chord, but a chord is not necessarily a diameter.<\/p>\n
tangent<\/strong><\/p>\na line on the outside of the circle that touches the circle at only one point. the radius of the circle that touches that point forms a right angle with the tangent line.<\/p>\n
central angle<\/strong><\/p>\nthe angle that is formed by two radii.<\/p>\n","protected":false},"excerpt":{"rendered":"
math problems about circles may look intimidating at first, so this post breaks down what to look out for when dealing with circles on act math.<\/p>\n","protected":false},"author":158,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[90],"tags":[],"ppma_author":[24918],"acf":[],"yoast_head":"\n
act math: how to solve circle problems<\/title>\n \n \n \n \n \n \n \n \n \n \n \n \n \n \n \n \n \n \n\t \n\t \n\t \n