Grade 9 Mathematics - Term III Review Flashcards

Vocabulary flashcards covering geometry formulas, polygon nomenclature, paper and screen sizing conventions, and statistical measures based on the Grade 9 Term III Review Sheet.

Regular polygon

A polygon that has all sides of equal length and all interior angles of equal measure.

Sum of the angles for a polygon

The total of all interior angles calculated using the formula $(n-2) \times 180^\circ$, where $n$ is the number of sides.

Pentagon

A polygon with $5$ sides and $5$ angles.

Hexagon

A polygon with $6$ sides and $6$ angles.

Heptagon

A polygon with $7$ sides and $7$ angles.

Octagon

A polygon with $8$ sides and $8$ angles.

Nonagon

A polygon with $9$ sides and $9$ angles.

Decagon

A polygon with $10$ sides and $10$ angles.

Perimeter of a circle (Circumference)

The distance around a circle, calculated as $2 \times \pi \times r$ or $\pi \times d$.

Area of a Parallelogram

The region inside the shape, calculated as $\text{base} \times \text{height}$.

Area of a Trapezium

The region inside the shape, calculated as $\frac{1}{2} \times (a + b) \times h$, where $a$ and $b$ are the lengths of the parallel sides.

Volume of a Sphere

The amount of space inside a sphere, calculated as $\frac{4}{3} \pi r^3$.

Volume of a Cone

The amount of space inside a cone, calculated as $\frac{1}{3} \pi r^2 h$.

Volume of a Cylinder

The amount of space inside a cylinder, calculated as $\pi r^2 h$.

Screen dimensions determination

Screen sizes (e.g., $14''$ or $32''$) are determined by the length of the diagonal across the screen.

Relationship between Paper Sizes (A-format)

Each subsequent format (e.g., A1, A2) is obtained by cutting the previous larger format (e.g., A0, A1) in half.

Mean

The average value of a data set, calculated by dividing the sum of all values by the total number of values.

Median

The middle value of a data set when the values are arranged in ascending or descending order.

Mode

The value that appears most frequently in a given data set.

Range

The difference between the maximum value and the minimum value ($\text{Maximum} - \text{Minimum}$) in a data set.

Interquartile range (IQR)

The difference between the upper quartile ($Q_3$) and the lower quartile ($Q_1$).

Five-number-summary

A summary consisting of the minimum, lower quartile, median, upper quartile, and maximum.

Box-and-whisker plot

A graphical representation of the five-number-summary, showing the distribution and spread of data.

Consistency (Statistics)

A measure of how spread out the data is; a group with less variation (smaller range or IQR) is considered more consistent.