Re: In the quadrilateral given above, AB = AD =10, BC = CD = 5. Which of
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10 Jan 2025, 07:20
As $\(\mathrm{AB}=\mathrm{AD}=10 \& \mathrm{BC}=\mathrm{CD}=5\)$, so the opposite angles must also be equal.
If angle BAD is 60 degrees, the triangle ABD becomes equilateral and side BD comes 10 , which in triangle $\(B C D\)$ gives $\(B C+C D=5+5=10=B D\)$, which is not possible as the sum of the sides in a triangle is always greater than the third side.
To satisfy $\(\mathrm{BC}+\mathrm{CD}>\mathrm{BD}\)$, the length of BD must be less than 10 which implies the measure of angle opposite to side BD in triangle ABD must be less than 60 .
Hence only option (A) i.e. 45 degrees can be the measure of angle BAD, so is correct.