advertisement

GPS Geometry UNIT QUESTION: What special properties are found with the parts of a circle? Standard: MM2G1, MM2G2 Today’s Question: How do we use angle measures to find measures of arcs? Standard: MM2G3.a,d Central Angle : An Angle whose vertex is at the center of the circle A Major Arc Minor Arc More than 180° Less than 180° P ACB To name: use 3 letters AB C B <APB is a Central Angle To name: use 2 letters Semicircle: An Arc that equals 180° E D To name: use 3 letters EDF P F THINGS TO KNOW AND REMEMBER ALWAYS A circle has 360 degrees A semicircle has 180 degrees Vertical Angles are Equal measure of an arc = measure of central angle A E Q m AB = 96° m ACB = 264° m AE = 84° 96 B C Arc Addition Postulate A C B m ABC = m AB + m BC Tell me the measure of the following arcs. m DAB = 240 m BCA = 260 D C 140 R 40 100 80 B A Congruent Arcs have the same measure and MUST come from the same circle or of congruent circles. C B 45 A 45 D 110