15th Grade Geometry Lines & Angles Lauri HagieIDT 503Final Project
2Lines Lines have arrows on each end. Lines do not end; they go on and on forever in both directions.
3Line Segments Line segments may also be called segments. Line segments are part of a line.Line segments do not have arrows.
4Rays Rays begin with a point at one end. Rays go on and on forever in only one direction.Rays have an arrow on one end.
5Horizontal Lines, segments, and rays may be drawn horizontally. Horizontal means level with the horizon.The horizon is the line in the distance where the land and the sky meet.Horizontal LineHorizontal SegmentHorizontal Rays
6Vertical Lines, segments, and rays may be drawn vertically. Vertical SegmentLines, segments, and rays may be drawn vertically.Vertical means straight up and down.Vertical Rays
7Oblique Lines, segments, and rays may be oblique. Oblique SegmentLines, segments, and rays may be oblique.Oblique means slanted.Oblique Rays
8Parallel Lines, segments, and rays may be parallel. Parallel, Oblique LinesLines, segments, and rays may be parallel.Parallel lines go in the same direction and will never cross over each other.Parallel lines can be horizontal, vertical or oblique.Parallel, Horizontal SegmentsParallel, Vertical Rays
9Intersecting Lines, segments, and rays may cross over each other. We call this intersecting.Intersecting SegmentsIntersecting Rays
10Perpendicular Lines, segments, and rays may be perpendicular. When lines intersect and form square corners, we call them perpendicular.Perpendicular SegmentsPerpendicular Rays
11Angles Angles form when lines, segments, or rays intersect. There are 3 types of angles:AcuteRightObtuse
12Right AnglesRight angles are 90They form square corners.
13Acute AnglesAcute angles are less than 90“A cute” little angle.
26Your answer was not correct. Try again. Sorry…Your answer was not correct. Try again.
27You are now a 5th grade expert in geometry! The EndYou are now a 5th grade expert in geometry!Hake, S., & Saxon, J. (2001) Math 65: an incremental development, 2nd edition. Norman, OK: Saxon Publishers, Inc.