search
Q: The instrument used for checking out right angles is known as ______.
  • A. Ghat tracer/घाट ट्रेसर
  • B. Levelling staff/लेवलिंग (समतलन) स्टाफ
  • C. Target prism/टार्गेट प्रिज्म
  • D. Optical square/प्रकाशीय समकोण दर्शक यंत्र
Correct Answer: Option D -
answer image

Explanations:

explanation image