Question

Which line is drawn first, before drawing a symmetry diagram?

• A. Base line
• B. Perpendicular line
• C. 45° line
• D. 30° line

Hint:

The base line (axis of symmetry) is the foundation for symmetry diagrams, ensuring accurate mirroring of shapes.

Answer 1

The Correct Option is A

Explaining symmetry diagrams
Step 1: A symmetry diagram in technical drawing often involves creating a figure with reflective or rotational symmetry, starting with a reference line.
Identifying the first line
Step 2: The base line, or axis of symmetry, is drawn first to serve as the reference for mirroring or aligning symmetrical elements.
Evaluating options
Step 3: Analyze the options:
- (A) Base line: Correct, as it defines the axis of symmetry.
- (B) Perpendicular line: Incorrect, as it may be drawn later for specific features.
- (C) 45° line: Incorrect, as angled lines are not typically the starting point.
- (D) 30° line: Incorrect, as it is not standard for symmetry.
Thus, the correct answer is (A).