17th?

Asked by smanishkumar2002 | 4th Aug, 2018, 08:34: PM

Expert Answer:

According to the question,
let ABC is an equilateral triangle with equation of BC x + y = 2 and vertex A (2, -1).
First we will find the perpendicular distance from vertex A on BC such that AD is perpendicular to BC.
begin mathsize 16px style open vertical bar fraction numerator straight x plus straight y minus 2 over denominator square root of 1 plus 1 end root end fraction close vertical bar equals open vertical bar fraction numerator 2 minus 1 minus 2 over denominator square root of 1 plus 1 end root end fraction close vertical bar equals fraction numerator 1 over denominator square root of 2 end fraction end style= AD
In ΔADB,
begin mathsize 16px style sin 60 degree equals fraction numerator square root of 3 over denominator 2 end fraction
AD over AB equals fraction numerator square root of 3 over denominator 2 end fraction
fraction numerator begin display style fraction numerator 1 over denominator square root of 2 end fraction end style over denominator AB end fraction equals fraction numerator square root of 3 over denominator 2 end fraction
AB equals fraction numerator 1 over denominator square root of 2 end fraction cross times fraction numerator 2 over denominator square root of 3 end fraction equals fraction numerator 1 over denominator square root of 6 end fraction end style

Answered by Sneha shidid | 6th Aug, 2018, 10:56: AM