In this topic, students will:
recognize and draw lines, rays, and angles with different measures
find the measure fo an angle that turns through a fraction of a circle
use known angle measures to measure unknown angles
use a protractor to measure and draw angles
use addition and subtraction to solve problems with unknown angle measures
Vocabulary:
Point - an exact location in space
Line - a straight path of points that goes on and on in opposite directions
Line segment - a part of a line with two endpoints
Ray - a part of a line that has one endpoint and continues on forever in one direction
Right angle - an angle that forms a square corner and has a measure of 90°
Acute angle - an angle that is open less than a right angle and has a measure less than 90°
Obtuse angle - an angle that is open more than a right angle but less than a straight angle. This angle measures between 90° and 180°
Straight angle - an angle that forms a straight line and has a measure of 180°
Degree (°) - angles can be measured using a unit called a degree
Unit angle - an angle that turns through 1/360 of a circle and measures 1° is called a unit angle or a one-degree angle
Angle measure - the number of degrees an angle turns through
Protractor - a tool used to measure and draw angles
Vertex - the point where two rays meet to form an angle