Elementary Educators III
1. degrees - ANSWER The units in which angles are measured, denoted by the
symbol °.
2. adjacent - ANSWER Next to.
3. chord - ANSWER A line segment that spans a circle. Each end of the line
segment is on the edge of the circle.
4. congruent - ANSWER Figures with the same size and shape.
5. diagonal - ANSWER A line segment with vertices as endpoints that is not
an edge.
6. rhombus - ANSWER Quadrilateral with four equal sides, equal opposite
angles, and two sets of parallel opposite sides.
7. horizontal line - ANSWER A line that runs left to right on the coordinate
plane, parallel to the x-axis. It has no rise, or change in y-value.
8. Pythagorean theorem - ANSWER The sum of each of the shortest sides
squared equals the longest side squared.
,9. circumference - ANSWER The distance around a circle.
10.coordinate plane - ANSWER A tool used for graphing that is a display of a
two dimensional plane. It consists of an x-axis and a y-axis: the x-axis being
a horizontal number line, the y-axis is a vertical number line, and the axes
meet at the origin.
11.y-axis - ANSWER The vertical line that passes through the origin on a
coordinate plane.
12.pentagon - ANSWER A polygon with 5 sides and 5 angles.
13.dilation - ANSWER A transformation that produces an image that is the
same shape as the source figure but a different size. These enlarge or reduce
a polygon by a specific scale factor in relation to a given center point.
14.symmetry - ANSWER The quality of having the same shape on either side
of a central line. In data analysis, the quality of the data having the same
shape on both sides of the mean.
15.transformation - ANSWER A change to the orientation of a shape.
16.similar - ANSWER Two figures have this property if they have the same
shape but not necessarily the same size.
17.ordered pair - ANSWER Two numbers written in the form (x, y), where x
represents the x-value or x-coordinate, and y represents the y-value or y-
coordinate.
, 18.reflective symmetry - ANSWER A shape which has the property that if it is
reflected about a line, the two sides will be identical.
19.translation - ANSWER A transformation that moves a source figure in a
specified direction for a specified distance.
20.scale factor - ANSWER The ratio of sides of two similar geometric figures.
21.reflection - ANSWER An image in which every point is the same distance
from a line as a corresponding point on the opposite side of the line.
22.proportion - ANSWER A true statement in which two ratios are equal to
each other.
23.image - ANSWER In translations on the coordinate plane, this is the figure
that results from the transformation.
24.distance formula - ANSWER A formula for calculating the distance
between two coordinates.
25.line of reflection - ANSWER A line directly in the middle of two reflected
images. All reflected points in the images are the same distance from this
line as one another.
26.prime mark - ANSWER A mark used to indicate images are the same even
after transformations.
27.quadrants - ANSWER The four sections of the coordinate plane, separated
and defined by the x-axis and y-axis.