DepEd MELC reviewer for Grade 8 Mathematics, Quarter 3. Study the rules, worked formulas, and exam hacks below.
1
If-Then Statements and Reasoning
A conditional is "If p, then q." Its converse swaps p and q; the contrapositive negates and swaps (always logically equivalent).
2
Triangle Congruence
| Postulate | Means |
|---|---|
| SSS | Three sides equal |
| SAS | Two sides + included angle |
| ASA | Two angles + included side |
| AAS | Two angles + non-included side |
⚠️ Common Mistake
There is NO "SSA" or "AAA" congruence. AAA only proves similarity, not congruence.
3
Parallel Lines and Transversals
When a transversal cuts parallel lines: corresponding angles are equal, alternate interior angles are equal, co-interior angles are supplementary.
4
Converse Example
Statement: "If it rains, the ground is wet."
| Form | Statement |
|---|---|
| Converse | If the ground is wet, it rained |
| Contrapositive | If the ground is not wet, it did not rain |
⚠️ Common Mistake
A true statement does not guarantee its converse is true.
📌 Quick Recap — Master These
Before your test, make sure you can confidently do each of the following:
- Explain and apply If-Then Statements and Reasoning.
- Explain and apply Triangle Congruence.
- Explain and apply Parallel Lines and Transversals.
- Explain and apply Converse Example.
Re-read any section above where you hesitate, then try the worked example again without looking.