click below
click below
Normal Size Small Size show me how
Grade 7 Chapter 7
Foundations for Geometry
| Question | Answer |
|---|---|
| acute angle | An angle that measures less than 90 degrees. |
| acute triangle | A triangle with all angles measuring less than 90 degrees. |
| angle | A figure formed by two rays with a common vertex. |
| center of rotation | The point about which a figure is rotated. |
| complementary angles | Two angles whose measures add up to 90 degrees. |
| congruent | Having the same size and shape. |
| correspondence | The relationship between two or more objects that are matched. |
| equilateral triangle | A triangle with three congruent sides. |
| image | A figure resulting from a transformation. |
| isosceles triangle | A triangle with at least two congruent sides. |
| line | A straight path that extends without end in opposite directions. |
| line of symmetry | the imaginary "mirror" in line symmetry. |
| line symmetry | One half of a figure is a mirror image of the other half. |
| obtuse angle | An angle whose measure is greater that 90 degrees but less than 180 degrees. |
| obtuse triangle | A triangle containing one obtuse angle. |
| parallel lines | Lines in a plane that do not intersect. |
| parallelogram | A quadrilateral with two pairs of parallel sides. |
| perpendicular lines | Lines that intersect to form right angles. |
| plane | A flat surface that extends forever. |
| point | An exact location in space. |
| polygon | A close plane figure formed by three or more line segments that intersect only at their endpoints. |
| ray | A part of a line that starts at one endpoint and extends forever. |
| rectangle | A parallelogram with four right angles. |
| reflection | A transformation of a figure that flips the figure across a line. |
| regular polygon | A polygon with congruent sides and angles. |
| regular tessellation | A regular polygon is repeated to fill a plane. |
| rhombus | A parallelogram with all sides congruent. |
| right angle | An angle that measures 90 degrees. |
| right triangle | A triangle containing a right angle. |
| rise | The vertical change when,the slope of a line is expressed as the ratio rise/run, or "rise over run". |
| rotation | A transformation in which a figure is turned around a point. |
| rotational symmetry | When a figure can be rotated less than 360 degrees around a central point and coincides with the original figure. |
| run | The horizontal change when,the slope of a line is expressed as the ratio rise/run, or "rise over run". |
| scalene triangle | A triangle with no congruent sides. |
| segment | A part of a line between two endpoints. |
| slope | A measure of the steepness of a line on a graph; the rise divided by the run. |
| square | A rectangle with four congruent sides. |
| supplementary angles | Two angles whose measures have a sum of 180 degrees. |
| tessellation | A repeating pattern of plane figures that completely cover a plane with no gaps or overlaps. |
| transformation | A change in the size or position of a figure. |
| translation | A movement (slide) of a figure along a straight line. |
| transversal | A line that intersects two or more lines. |
| trapezoid | A quadrilateral with exactly one pair of parallel sides. |
| Triangle Sum Theorem | The measures of the angles in a triangle add up to 180 degrees. |
| vertical angles | A pair of opposite congruent angles formed by intersecting lines. |