Survey
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Measuring and Constructing Angles section 1-3 angle - a figure formed by two rays (sides) with a common endpoint (vertex) (the plural is vertices). An angle can be named by its vertex, by a point on each ray plus the vertex, or by a number. A X 2 or or AXB 2 B X A C AXB or 2 but not X X Why not? 2 B Angles can be measured on paper with a protractor or in the three-dimensional world with a transit. Angles are measured in units called degrees. Since a circle contains 360 , then each degree comprises 1/360 th of the circle. You can use the Protractor Postulate to help you classify angles by their measure. The measure of an angle is the absolute value of the difference of the real numbers that the rays correspond with on a protractor. If OC corresponds with c and OD corresponds with d, then m DOC = |d – c| or |c – d|. problem # 1 - Find the measure of each angle below and decide whether it is acute, right, or obtuse. a. YXW b. YXZ c. UXW U congruent angles - angles that have the same measure. * In a diagram, arc marks may be used to indicate that two angles are congruent. P A AXB X PYQ Q B Y * The Angle Addition Postulate is very similar to the Segment Addition Postulate that we learned in the last lesson. problem # 2 - m DEG = 115°, and m DEF = 48°. Find m FEG. angle bisector - a ray that divides an angle into two congruent angles. JK bisects LJK LJM. Therefore, KJM. problem # 3 - KM bisects JKL, m JKM = (4x + 6)°, and m MKL = (7x – 12)°. Find m JKM. Constructing a Congruent Angle Constructing an Angle Bisector