Verified Solution • 2025–26 Session moderate

QJEEM22Ma8b5a: JEE Main 2022 Mathematics - Class 11 JEEM22Ma8b5a Solution: Let R be the point (3, 7) and let P and Q be two points on the…

Let R be the point (3, 7) and let P and Q be two points on the line x + y = 5 such that PQR is an equilateral triangle. Then the area of Δ\Delta PQR is :

Multiple Choice Options

  • A 2543{{25} \over {4\sqrt 3 }}
  • B 2532{{25\sqrt 3 } \over 2}
  • C 253{{25} \over {\sqrt 3 }}
  • D 2523{{25} \over {2\sqrt 3 }}

Step-by-Step Verified Solution

JEE Main 2022 (Online) 26th June Morning Shift Mathematics - Straight Lines and Pair of Straight Lines Question 58 English Explanation

Let, side of triangle = a.

h=∣3+7−5∣12+12h = {{|3 + 7 - 5|} \over {\sqrt {{1^2} + {1^2}} }}

=52= {5 \over {\sqrt 2 }}

From figure, h=asin⁡60∘h = a\sin 60^\circ

⇒a=2h3\Rightarrow a = {{2h} \over {\sqrt 3 }}

=23×52= {2 \over {\sqrt 3 }} \times {5 \over {\sqrt 2 }}

=106= {{10} \over {\sqrt 6 }}

∴\therefore Area =34(106)2= {3 \over 4}{\left( {{{10} \over {\sqrt 6 }}} \right)^2}

=2523= {{25} \over {2\sqrt 3 }}

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