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· 1 Months ago

Is the triangle an equilateral one?

Question:

In the adjoining figure ACB is a quadrant with radius a. A semicircle is drawn outside the quadrant taking AB as a diameter. Find the area of shaded region:



Options:
A) \(\cfrac{1}{4}(\pi -2a^2)\)
B) \(\cfrac{1}{4}(\pi a^2 -a^2)\)
C) \(\cfrac{a^2}{2}\)
D) Cant be determined
Solution:
Ans: (c)

 In triangle ABC by PGT

\(AB^2=AC^2+BC^2\) 

\(AB^2=a^2+a^2 = 2a^2 \)
\(AB=a\sqrt{2}\)

Area of shaded region = Area of semicircle - (Area of sector ACB - Area of \(\triangle\)ABC)

\(=\cfrac{1}{2}\pi \cfrac{a^2}{2}-\left ( \cfrac {1}{4}\pi a^2-\cfrac{1}{2}a^2 \right )\)

\(=\cfrac{\pi a^2}{4}-\cfrac{\pi a^2}{4}+\cfrac{1}{2}a^2=\cfrac{1}{2}a^2\)

Abhishek Shrivastava

· commented

· 1 Months ago

Dear Student

Given answer is correct and given triangle is a Right angle triangle
keep learning with us

Regards
Team TR

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