Join the Most Relevant JEE Main 2025 Test Series & get 99+ percentile! Join Now
Search any question & find its solution
Question: Answered & Verified by Expert
If the angles of a triangle are $30^{\circ}$ and $45^{\circ}$ and the included
side is $(\sqrt{3}+1)$, then what is the area of the tringle?
MathematicsProperties of TrianglesNDANDA 2013 (Phase 2)
Options:
  • A $\frac{\sqrt{3}+1}{2}$
  • B $2(\sqrt{3}+1)$
  • C $\frac{\sqrt{3}+1}{3}$
  • D $\frac{\sqrt{3}-1}{2}$
Solution:
1168 Upvotes Verified Answer
The correct answer is: $\frac{\sqrt{3}+1}{2}$


From $\Delta \mathrm{ADB}, \mathrm{AD}=\mathrm{BD}=\mathrm{x}$
In $\Delta \mathrm{ADC}$
$\tan 30^{\circ}=\frac{\mathrm{x}}{\sqrt{3}+1-\mathrm{x}}$
$\Rightarrow \frac{1}{\sqrt{3}}=\frac{\mathrm{x}}{\sqrt{3}+1-\mathrm{x}} \Rightarrow \sqrt{3} \mathrm{x}=\sqrt{3}+1-\mathrm{x}$
$\Rightarrow(\sqrt{3}+1) \mathrm{x}=\sqrt{3}+1$
$x=\frac{\sqrt{3}+1}{\sqrt{3}+1}=1$
Area of $\triangle \mathrm{ABC}=\frac{1}{2} \times(\sqrt{3}+1) \times 1=\frac{\sqrt{3}+1}{2}$

Looking for more such questions to practice?

Download the MARKS App - The ultimate prep app for IIT JEE & NEET with chapter-wise PYQs, revision notes, formula sheets, custom tests & much more.