Triangulation MCQ with answer and solution

Concept

Geometric strength of triangles in triangulation surveys, ensuring no excessive error propagation due to acute or obtuse angles.

Step-by-step solution

1. Understand the definition of a well-conditioned triangle in surveying. 2. Recall the standard geometric limits for triangulation: angles should ideally lie between 30° and 120°. 3. Identify the maximum limit from the given options, which is 120°.

Explanation

In triangulation surveys, a well-conditioned triangle is one in which the angles do not cause small errors in measurements to be magnified in the computed sides. Practically, to ensure good geometric strength, no angle in a well-conditioned triangle should be less than 30° or more than 120° (often ideally equilateral with 60°). Therefore, the maximum limit for angles in a well-conditioned triangle is 120°.

Why the other options are wrong

A: 45° is well below the upper limit. B: 60° is the ideal angle for an equilateral triangle, not the maximum limit. C: 90° is an arbitrary right angle, not the triangulation limit.

Shortcut

Remember the angle range for a well-conditioned triangle: 30° to 120°.

Common mistake

Confusing 120° with 90° or 60°; 60° is the ideal angle for an equilateral triangle, but angles up to 120° are acceptable in a well-conditioned triangle.