# Basic Geometry Terms Point Line Ray Line Segment

Basic Geometry Terms Point Line Ray Line Segment Angles: Acute, Obtuse, Straight, Right Angle Pairs: Congruent, Vertical, Adjacent, Complementary and Supplementary Lines: Parallel, Perpendicular, Intersecting Triangles: Side Classification Angle Classification. Polygons Angle Congruent Figures/Similar Figures Vertex Symmetry Plane Circles Translation, Rotation, Reflection

QUIZ Point – an exact location in space. It is ALWAYS named with a capital letter. Example: Point P . P

QUIZ Line – a straight path of point that continues infinitely in two directions. A line is named by any two points on it. Example: Line AB or AB A B

QUIZ Line segment- a part of a line that begins at one point and ends at another point. Example: Line Segment EF, or EF E F

QUIZ Ray - this has one endpoint and continues infinitely in one direction. Example: Ray CD, or CD C D

QUIZ Angle – a figure formed by two rays that have the same end point. X Angle Y, angle XYZ, angle ZYX Y Y XYZ ZYX Z

QUIZ Vertex – An angle is named by its vertex or by three points with its vertex in the middle. Example: Z (Vertex ) Y X

QUIZ Plane – a flat surface. It continues in all directions. It is usually named with a small letter. Example: Plane m

QUIZ Straight Angle - this measures 180 Right Angles – this measures 90 Obtuse Angle - measures more than 90 but less than 180 Acute Angle - measures less than 90

QUIZ Intersecting Lines – Lines that meet Perpendicular Lines – Lines that intersect and form right angles. Parallel Lines – Lines in a plane that never intersect.

QUIZ SIDE CLASSIFICATION Equilateral Isosceles Scalene - all three sides are equal. - two sides are equal - none of the sides are equal ANGLE CLASSIFICATION Acute Right - all angles - one angle measure less than is 90 degrees Obtuse - one angle measures more than 90 degrees

QUIZ Number of sides Name Picture 3 Triangle 4 Quadrilateral 5 Pentagon 6 Hexagon 7 Heptagon 8 Octagon 9 Nonagon 10 Decagon

QUIZ Congruent Figures are EXACTLY the same size AND shape. ~ Example: Rectangle A is = Rectangle B Reminder: ~ = means A B congruent Similar Figures are the shape, but different sizes. Example: Square C ~ Square D C ~ means similar to D

QUIZ A shape has symmetry when you can fold one half over the other half perfectly. Examples: These figures do not have any lines of symmetry:

QUIZ T U R V W S Name Definition Example Chord A line segment that has endpoints on the circle TU Diameter Radius Central angle A chord that passes through the center of a circle. It is twice the length of a radius. A line segment that extends from the center to any point on the circle. It is half the size of a diameter An angle that has its vertex at the center of the circle. SV RW SRW

QUIZ Translation - when you slide the figure along a straight line. Reflection – when you flip the figure along a line of symmetry. The new figure is called a reflection. Rotation – you turn the figure on a curved path around a point. . Point of rotation

Congruent Angles: Same measure Vertical Angles: A pair of angles formed by intersecting lines. (Hint: Think of the angle on the opposite side. ) 30 º MORE…

Adjacent Angles – A pair of angles with a common vertex and a common side. (hint: they’re next to each other) Complimentary Angles: Angles that add up to 90º. 60º 30º Supplementary Angles: Angles that add up to 180 º. 100º 80º

1. What do you call a six sided polygon? a. Heptagon b. Hexagon c. Decagon d. quadrilateral 2. What do you call a triangle with no equal sides? a. Scalene b. Obtuse c. Isosceles d. Equilateral 3. An angle that measures 91 degrees is an _____ angle. a. Right b. Obtuse c. Straight d. Acute c. Polygon d. Decagon 4. A ten sided polygon is called a. Tenagon b. Nonagon 5. Which letter is the vertex in this angle? Angle PHY 6. a. P vertex b. H c. Y d. there is no

6. Two lines that will never meet are called: a. Parallel lines b. Perpendicular lines c. Intersecting lines 7. Two lines that form right angles when they meet are called: a. Parallel lines b. Perpendicular lines c. Intersecting lines 8. Two lines that cross but do not necessarily form right angles are called: a. Parallel lines b. Perpendicular lines c. Intersecting lines 9. What kind of a triangle has one obtuse angle and two acute angles? 10. a. Acute triangle b. Obtuse triangle c. Right triangle

10. What kind of triangle has three acute angles? a. Acute triangle b. Obtuse triangle c. Right triangle 11. What kind of triangle has one right angle? a. Acute triangle b. Obtuse triangle c. Right triangle 12. When a figure can be folded in half perfectly this is called: a. Congruent b. Similar c. Symmetry d. Chord 13. Two figures that are exactly the same shape and size are called: a. Congruent b. Similar c. Symmetry d. Chord 14. Two figures that are the same shape but different sizes are called a. Congruent b. Similar c. Symmetry d. Chord

15. A triangle has one angle that measures 45 degrees, another that measures 30, what is the third angle? a. 95 b. 5 c. 105 d. 75 16. In a circle the line that starts at the center and then stops at any point on the circle is called the a. Radius b. Diameter c. Chord d. Center 17. In a circle the line that starts at one point on the circle, travels through the center and then to another point on a circle is called a. Radius b. Diameter c. Chord d. Center 18. In a circle the line that starts at one point on the circle and travels to another point on a circle is called a. Radius b. Diameter c. Chord d. Center

19. A figure that starts at one point and stops at another is called a: a. Line segment b. Line c. ray d. Point 20. A figure that starts at one point and then travels on forever in another direction is called: a. Line segment b. Line c. ray d. Point 21. A figure that goes on forever in both directions is called a a. Line segment b. Line c. ray d. Point 22. An exact location is called a. Line segment b. Line

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