Self-Study Workbook · Math Fundamentals

Pre-Algebra & Geometry
Terminology

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📐 Section 01

Pre-Algebra Terminology

Q 01 Variable

A letter that represents an unknown number is called a ___.

💡 Memory: Variable = Vary = can CHANGE. x, y, n are variables.

Example

In 3x + 5 = 11, the letter x is the ___.
→ It could be 1, 2, or any number until you solve it.

Q 02 Coefficient

The number multiplied by a variable is called the ___.

💡 Memory: Co- = together. Coefficient "comes with" the variable. In 7x, 7 is the ___.

Example

4y² − 3y + 9
• coefficient of = 4
• coefficient of y = −3
• 9 is a constant (no variable attached)

Q 03 Constant

A number with no variable — its value never changes — is called a ___.

💡 Memory: Constant = CONSTant = stays the SAME. Like 5 always means 5.

Practice

In 6a − 8 = 10, which numbers are constants? → −8 and 10

Q 04 Like Terms

Terms that have exactly the same variable and exponent are called ___.

💡 Memory: Like = Same. 3x and 5x are LIKE; 3x and 3x² are NOT.

Tricky Case — don't mix up!

2x² + 5x² → can combine → 7x²
2x² + 5x → CANNOT combine ❌ (exponents differ)

Q 05 Distributive Property

The rule a(b + c) = ab + ac is called the ___ property.

💡 Memory: Distribute = GIVE OUT. Multiply the outside number to EVERY term inside the parentheses.

Example

3(x + 4) = 3·x + 3·4 = 3x + 12
Common mistake: 3(x + 4) ≠ 3x + 4 ← forgot to distribute to 4!

Q 06 Equation

A mathematical statement that shows two expressions are equal (uses an "=" sign) is called an ___.

💡 Memory: Equation = Equal. Must have =. Without = it's just an expression.

Equation vs. Expression

2x + 3Expression (no "=" sign)
2x + 3 = 7Equation (has "=" sign) ✅

Q 07 Exponent

In 53, the small raised number 3 is called the ___. It tells you how many times to multiply the base by itself.

💡 Memory: Exponent = how many times EXPand the multiplication. 5³ = 5×5×5

Watch out!

23 = 8 ← not 6! (2×3 = 6 is WRONG)
23 means 2 × 2 × 2 = 8

Q 08 Absolute Value

The distance from a number to zero on the number line — always non-negative — is called its ___.

💡 Memory: Absolute = TOTALLY positive. |−7| = 7, |7| = 7. Distance is never negative!

Common Trap

|−5| = ? → Answer: 5 (not −5)
−|5| = ? → Answer: −5 (negative sign is OUTSIDE the bars)

Q 09 Inequality

A mathematical statement that compares two values using <, >, ≤, ≥, or ≠ is called an ___.

💡 Memory: Inequality = NOT Equal. The symbol "gobbles" the bigger number: the open side faces the bigger value.

Reading Practice

x > 3 → "x is greater than 3"
x ≤ 5 → "x is less than or equal to 5"
⚠️ When you multiply/divide by a negative, FLIP the sign!

Q 10 Order of Operations

The rule that says you must solve parentheses → exponents → multiply/divide → add/subtract in that order is called ___.

💡 Memory: PEMDAS — Please Excuse My Dear Aunt Sally.
(Parentheses, Exponents, Multiplication, Division, Addition, Subtraction)

Classic Trap

2 + 3 × 4 = ?
Wrong: 2+3=5, then 5×4=20
Right: 3×4=12, then 2+12=14


📏 Section 02

Geometry Terminology

Q 11 Perimeter

The total distance around the outside of a shape is called its ___.

💡 Memory: Peri = around (like "periphery"). Add ALL the sides.

Example — Rectangle 6 × 4

Perimeter = 6 + 4 + 6 + 4 = 20
Or: P = 2(l + w) = 2(6+4) = 20
⚠️ Don't confuse with Area (which uses × not +)

Q 12 Area

The amount of space inside a 2D figure, measured in square units, is called its ___.

💡 Memory: Area = inside space. Always in SQUARE units (cm², m², ft²).

Key Formulas

Rectangle: A = l × w
Triangle: A = 12 × b × h
Circle: A = πr²

Q 13 Parallel Lines

Lines in the same plane that never intersect and are always the same distance apart are called ___ lines.

💡 Memory: Parallel = the two "l"s in the word never touch — just like the lines! Marked with arrows →→

vs. Perpendicular

Parallel: same direction, never meet ∥
Perpendicular: meet at exactly 90° ⊥

Q 14 Congruent

Two figures that have exactly the same shape AND size are called ___.

💡 Memory: Congruent ≅ means = for shapes. Same size, same shape. (Similar = same shape, different size.)

Congruent vs. Similar

🔷🔷 Two identical triangles → Congruent
🔷🔹 One big, one small triangle → Similar (same angles, different size)

Q 15 Hypotenuse

In a right triangle, the side opposite the right angle — always the longest side — is called the ___.

💡 Memory: Hypo = under/beneath. It "reaches across" from the right angle. Used in: a² + b² = c² (c = hypotenuse)

Pythagorean Theorem

Legs: 3, 4 → 3² + 4² = c²
9 + 16 = 25c = 5
The side with length 5 is the hypotenuse.

Q 16 Supplementary Angles

Two angles that add up to 180° are called ___ angles.

💡 Memory: Supplementary = Straight (180° = straight line). Supplementary = Straight.
Complementary = Corner (90°). Complementary = Corner.

Quick Drill

If one angle is 110°, its supplement = 180° − 110° = 70°
If one angle is 35°, its complement = 90° − 35° = 55°

Q 17 Radius

The distance from the center of a circle to any point on its edge is called the ___.

💡 Memory: Radius is always HALF the diameter. r = d ÷ 2. One ray from center to edge.

Radius vs. Diameter vs. Circumference

radius r → diameter d = 2r → circumference C = 2πr
If radius = 5: diameter = 10, circumference ≈ 31.4

Q 18 Volume

The amount of 3D space a solid occupies, measured in cubic units, is called its ___.

💡 Memory: Volume = 3D space inside. Always CUBIC units (cm³, m³). Area = 2D (flat), Volume = 3D (solid).

Key Formulas

Rectangular prism: V = l × w × h
Cube (side s): V = s³
Cylinder: V = πr²h

Q 19 Vertex

The corner point where two sides of a polygon meet — or the tip of an angle — is called a ___.

💡 Memory: Vertex = V-shape = pointy TOP. Plural: vertices. A triangle has 3 vertices.

Count the Vertices

Triangle → 3 vertices
Rectangle → 4 vertices
Pentagon → 5 vertices
A shape always has the same number of sides as vertices!

Q 20 Circumference

The perimeter (distance around) of a circle is called its ___. Use the formula C = 2πr.

💡 Memory: Circum = around (circumnavigate = go around the globe). Circumference = distance around a circle.

Example

Circle with radius = 7:
C = 2 × π × 7 ≈ 2 × 3.14 × 7 ≈ 43.96
⚠️ Use diameter if given: C = πd