MENU
Question -

Find the equations to the sides of the triangles the coordinates of whose angular points are respectively:
(i) (1, 4), (2, -3) and (-1, -2)
(ii) (0, 1), (2, 0) and (-1, -2)



Answer -

(i)┬а(1, 4), (2, -3) and(-1, -2)

Given:

Points A (1, 4), B (2,-3) and C (-1, -2).

Let us assume,

m1,┬аm2,┬аandm3┬аbe the slope of the sides AB, BC and CA, respectively.

So,

The equation of theline passing through the two points┬а(x1, y1)and┬а(x2, y2).

Then,

m1 =┬а-7,┬аm2┬а=-1/3┬аand m3┬а= 3

So, the equation ofthe sides AB, BC and CA are

By using the formula,

y тАУ y1= m(x тАУ x1)

=> y тАУ 4 = -7 (x тАУ1)

y тАУ 4 = -7x + 7

y + 7x = 11,

=> y + 3 = (-1/3)(x тАУ 2)

3y + 9 = -x + 2

3y + x = тАУ 7

x + 3y + 7 = 0 and

=> y + 2 = 3(x+1)

y + 2 = 3x + 3

y тАУ 3x = 1

So, we get

y + 7x =11, x+ 3y + 7=0 and y тАУ 3x = 1

тИ┤ The equation of sidesare y + 7x =11, x+ 3y + 7 =0 and y тАУ 3x = 1

(ii)┬а(0, 1), (2, 0) and(-1, -2)

Given:

Points A (0, 1), B (2,0) and C (-1, -2).

Let us assume,

m1,┬аm2,┬аandm3┬аbe the slope of the sides AB, BC and CA, respectively.

So,

The equation of theline passing through the two points┬а(x1, y1)and┬а(x2, y2).

Then,

m1┬а=-1/2, m2┬а= -2/3┬аand m3= 3

So, the equation ofthe sides AB, BC and CA are

By using the formula,

y тАУ y1= m(x тАУ x1)

=> y тАУ 1 = (-1/2)(x тАУ 0)

2y тАУ 2 = -x

x + 2y = 2

=> y тАУ 0 = (-2/3)(x тАУ 2)

3y = -2x + 4

2x тАУ 3y = 4

=> y + 2 = 3(x+1)

y + 2 = 3x + 3

y тАУ 3x = 1

So, we get

x + 2y = 2, 2x тАУ 3y =4and y тАУ 3x = 1

тИ┤ The equation of sidesare x + 2y = 2, 2x тАУ 3y =4 and y тАУ 3x = 1

Comment(S)

Show all Coment

Leave a Comment

Free - Previous Years Question Papers
Any questions? Ask us!
×