Difficulty: Easy
Correct Answer: Correct
Explanation:
Introduction / Context:
 Traditional drafting uses fixed-angle triangles (45° and 30°/60°) with a T-square or straightedge to construct common angles. Combining these aids enables many additional angles without a protractor.
Given Data / Assumptions:
Concept / Approach:
 Using angle subtraction: 45° - 30° = 15°. By orienting one triangle against the other, the composite angle between a triangle edge and the baseline becomes 15°, allowing accurate construction of that angle.
Step-by-Step Solution:
Verification / Alternative check:
 Many drafting texts list standard composite angles achievable with triangles, including 15°, 75°, and others derived from sums/differences of 30°, 45°, and 60°.
Why Other Options Are Wrong:
 “Incorrect” would suggest the triangles are limited to only their nominal angles; in practice their combination yields additional precise angles.
Common Pitfalls:
 Slippage between triangles leading to angle error; misidentifying the 30° versus 60° side; forgetting to keep one edge firmly against the baseline.
Final Answer:
 Correct
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