9.Straight Line
normal

જો સમબાજુ ત્રિકોણનું એક શિરોબિંદુ ઊંગમબિંદુ પર હોય અને તેની બાજુની લંબાઇ $'a'$ હોય તથા બાકીના શિરોબિંદુઓ રેખા $x - \sqrt{3} y = 0$ પર હોય તો ત્રિકોણનું તૃતીય શિરોબિંદુ મેળવો 

A

$(0, a)$

B

$\left( {\frac{{\sqrt 3 \,a}}{2}\,\,,\,\, - \,\frac{a}{2}} \right)$

C

$(0, - a)$

D

ઉપરના બધા 

Solution

Slope of the line $x=\sqrt{3} y$ is $\frac{1}{\sqrt{3}}$ which is $30^{\circ}$ with the positive $x$ -axis. As it is an equilateral triangle the other vertex must be on $x=-\sqrt{3} y$

Let the side be $(x, y)$. Hence, $x^{2}+y^{2}=a^{2}$

$4 y^{2}=a^{2}$

$y=\pm \frac{a}{2}$

similarily, $x=\pm \frac{\sqrt{3} a}{2}$

Hence, if the triangle lies in the 1 st quadrant and 4 th quadrant vertex is $\left(\frac{\sqrt{3} a}{2},-\frac{a}{2}\right)$

If the triangle lies in the 2 nd and 3 rd quadrant the vertex is $\left(-\frac{\sqrt{3} a}{2},-\frac{a}{2}\right)$

Standard 11
Mathematics

Similar Questions

Start a Free Trial Now

Confusing about what to choose? Our team will schedule a demo shortly.