2**
**1. Algebra:**
**Introducing Variables:**
Variables are symbols that represent numbers. They are commonly used in algebra to generalize
mathematical statements. In algebraic expressions, variables can stand for unknown quantities. For example,
in the expression \(2x + 3\), \(x\) is a variable. We can assign values to variables to evaluate expressions.
**Simplifying Expressions:**
Expressions in algebra often involve combining like terms. Like terms are terms that have the same variable
raised to the same power. To simplify expressions, we add or subtract coefficients of like terms. For example,
to simplify \(3x + 2x\), we combine the coefficients of \(x\) to get \(5x\).
**Solving Equations:**
Equations are mathematical statements asserting that two expressions are equal. Solving equations involves
finding the value of the variable that makes the equation true. We use inverse operations to isolate the
variable. For example, to solve \(2x + 5 = 11\) for \(x\), we subtract 5 from both sides to get \(2x = 6\), then
divide both sides by 2 to find \(x = 3\).
**2. Geometry:**
**Angles:**
Angles are formed by two rays or line segments that share a common endpoint called the vertex. Review
types of angles including acute (less than 90 degrees), obtuse (greater than 90 degrees), and right angles
(exactly 90 degrees). Understanding angles is fundamental in geometry and helps in various geometric
calculations.
**Triangles:**
Triangles are polygons with three sides and three angles. They are classified based on their side lengths and
angle measures. Common types of triangles include equilateral (all sides and angles are equal), isosceles (two
sides and two angles are equal), and scalene (no sides or angles are equal) triangles.
**Quadrilaterals:**
Quadrilaterals are polygons with four sides. They include various shapes such as squares, rectangles,
parallelograms, rhombuses, and trapezoids. Each type of quadrilateral has unique properties related to its side
lengths, angle measures, and diagonals.
**3. Data Handling:**
**Collecting Data:**
Data collection involves gathering information through various methods such as surveys, experiments, and
observations. It is important to ensure that data collected is relevant and accurate to draw meaningful
conclusions.