Pre-AlgebraGeometry Terms: Plane Figures

5-1 and5-2  Terms: Points, Lines, and Planes

1. A _______________ is an exactlocation in space. It is usually represented as a dot,    but it has no size at all.

2. A _______________ is a straightpath that extends without end in opposite directions.

3. A _______________ is a part of aline. It has one endpoint and extends without end in one direction.

4. A ________________ is a part of aline or a ray that extends from one endpoint to another.

5. A ________________ is a perfectlyflat surface that extends infinitely in all directions.

6. ________________________ are pointsthat lie on the same line.

7. Figures are ___________________ ifthey have the same shape and same size.

8. A ________________ is a line thatintersects any two or more other lines.

5-1 and5-2  Terms: Angles

1. An _____________is formed by tworays with a common endpoint.

2. Two rays are the sides of an angle.This common endpoint is called the ______________.

3. A _________________ angle is anangle that measures exactly 90 degrees.

4. An _______________ angle is anangle that measures less than 90 degrees.

5. An ________________ angle is anangle that measures more than 90 degrees but less than 180 degrees.

6. A _________________ angle is anangle that measures exactly 180 degrees.

7. If the sum of the measures of twoangles is 90 degrees, then the angles are __________________ angles.

8. If the sum of the measures of twoangles is 180 degrees, then the angles are _______________ angles.

9. Intersecting lines form two pairsof __________________ angles.  Theopposite angles are always congruent.

5-2Terms: Parallel and Perpendicular Lines

1. When lines, segments, or raysintersect, they form angles. If the angles formed by two intersecting lines areequal to 90 degrees, the lines are _____________________ lines.

2. Some lines in the same plane do notintersect at all. These lines are _______________ lines.

3. _____________ lines do notintersect, and yet they are also not parallel.

4. ________________ angles are theopposite angles formed by two intersecting lines. These angles have the samemeasure, so they are congruent.

5. A _______________ is a line thatintersects any two or more lines. __________ angles are formed when atransversal intersects two lines. When those two lines are ____________, all ofthe acute angles formed are congruent, and all of the obtuse angles formed arecongruent. These obtuse and acute angles are ______________________.

5-3  Terms: Triangles

1. A ________________ triangle has nocongruent sides and no congruent angles.

2. An _________________ triangle has at least 2 congruent sides and 2congruent angles.

3. In an ________________________triangle all of the sides and all of the angles are congruent.

4. In an _______________ triangle, allof the angles are acute.

5. An _________________ triangle has one obtuse angle.

6. A _______________ triangle has oneright angle.

7. The Triangle Sum Theorem:  the sum of the angles in a triangle is _____degrees.

5-4Terms: Polygons

1. A ______________ is a closed planefigure formed by three or more line segments.

2. Each line segment forms a_____________ of the polygon, and meets, but does not cross.

3. A polygon with 3 sides and 3 anglesis called a ________________.

4. A polygon with 4 sides and 4 anglesis called a ____________________.

5. A polygon with 5 sides and 5 anglesis called a ____________________.

6. A polygon with 6 sides and 6 anglesis called a ____________________.

7. A polygon with 7 sides and 7 anglesis called a ______________________.

8. A polygon with 8 sides and 8 anglesis called an ____________________.

9. A polygon with 9 sides and 9 anglesis called a ____________________.

10. A polygon with 10 sides and 10angles is called a ____________________.

11. A __________________ polygon is apolygon in which all sides are congruent and all angles are congruent.

12. Explain why a circle is not apolygon.

Terms:Quadrilaterals

1. A ___________________ has two pairsof parallel sides.

2. A ___________________ has fourcongruent sides.

3. A ____________________ has fourright angles.

4. A ____________________ has fourcongruent sides and four right angles.

5. A _____________________ has exactlyone pair of parallel sides.

6. A _____________________ has exactlytwo pairs of congruent, adjacent sides.

7. The sum of the angles of a quadrilateralis ______ degrees.

5-7 Terms:Transformations

1. A _________________ changes theposition or orientation of a figure.

2. A _________________ is when afigure slides along a straight line without turning.

3. A _________________ is when afigure turns around a fixed point.

4. A _________________ is when thefigure flips across a line of reflection, creating a mirror image.

5. A _________________ enlarges orreduces a figure.