IIT-JEE 2000 ScreeningQuestion 1
A pole stands vertically inside a triangular park $\triangle ABC$. If the angle of elevation of the top of the pole from each corner of the park is same, then in $\triangle ABC$ the foot of the pole is at the
Trigonometric Ratio & Identities
Solution
Concept. For a fixed height $h$, the same elevation $\theta$ means the same distance $h\cot\theta$ from the foot. Formulas used. (1) Distance from the foot $=h\cot\theta$Step 1 - Equal distances. By (1), the foot $O$ satisfies $OA=OB=OC$. Step 2 - Conclude. The point inside the triangle equidistant from all three vertices is the circumcentre. Answer: (B)