Grade 3/4
An angle with a measure greater than 0° and less than 90°
Acute Angle
The intersection of the perpendicular axes of a coordinate grid. it is designated by the ordered pair (0, 0).
The Origin
Any number greater than 0.
A positive number
The result when one number is subtracted by another number (i.e., the “answer” to a subtraction computation).
Difference
The ratio of the vertical change compared to the horizontal change between two points on a coordinate grid. THIS is often expressed as rise over run or change in y change in x . A vertical line has an undefined THIS. A horizontal line has a THIS of 0. THIS is also called rate.
Slope
Two angles with a common side and a common vertex but no overlap.
Adjacent Angles
The horizontal axis of a coordinate grid
X-Axis
The middle number in a set of data ordered from least to greatest (or from greatest to least). If the data set consists of an even number of entries.
Median
A likelihood of an outcome based on the number of expected favorable outcomes compared to the number of possible outcomes.
Theoretical Probability
A formula that relates the lengths of the two legs and the hypotenuse of any right triangle. The Pythagorean theorem states the following: If a triangle is a right triangle and has two legs with lengths a and b and a hypotenuse with length c, then a2 + b2 = c2 .
Pythagorean Theorem
A polygon with exactly 8 sides.
Octagon
A pair of numbers or other elements in which the order of recording is consequential (i.e., order makes a difference).
Ordered Pair
A letter or symbol that represents a missing or unknown value. Generally, the letter is lowercase and italicized.
A Variable
A drawing that is geometrically similar to an original figure or object.
Scale Drawing
One of two equal factors (roots) of a number or expression. Informally, it can be thought of as “the number, when multiplied by itself, has a product equal to a given number.”
Square Root
Two or more lines that lie in the same plane and do not intersect.
Parallel Lines
One of the four regions into which the perpendicular axes divide a coordinate grid.
Quadrant
The sum of the areas of all the faces of a three-dimensional (solid) figure or object.
Surface Area
Two angles for which the sum of their measures is 180°.
Supplementary Angles
The transformation of a figure that produces the mirror image of the original figure.
Reflection
A polygon with exactly 10 sides
The line segment formed by the intersection of two faces of a threedimensional (solid) figure.
Edge
The magnitude of an expression under consideration. |x|
Absolute Value
The theorem that asserts the sum of the lengths of any two sides of a triangle is greater than the length of the third side.
Triangle Inequality Theorem
A form of exponential notation created by writing a number as the product of a decimal number multiplied by a power of 10 (e.g., 103 ). If the original number is positive, the decimal number must be greater than or equal to 1, but less than 10. If the original number is negative, the decimal number must be less than or equal to {1, but greater than {10.
Scientific Notation