Q 1 :

The perimeter of a triangle with vertices (0, 4), (0, 0) and (3, 0) is

  • 5 units

     

  • 12 units

     

  • 11 units

     

  • (7+5) units

     

(2)     12 units

 



Q 2 :

AD is a median of ABC with vertices A(5, –6), B(6, 4) and C(O, O). Length AD is equal to :

  • 68 units

     

  • 215 units

     

  • 101 units

     

  • 10 units

     

(1)

Using the mid point formula, the coordinates of mid-point of BC are

Co-ordinates of D(x,y)=(6+02,4+02)=(3,2)

Now, length of AD=(5-3)2+(-6-2)2=4+64=68

 



Q 3 :

If the distance between the points (3, –5) and (x, –5) is 15 units, then the values of x are :

  • 12, –18

     

  • –12, 18

     

  • 18, 5

     

  • –9, –12

     

(2)

Here, (15)2=(3-x)2+(-5+5)2

225=9-6x+x2x2-6x-216=0

x2-18x+12x-216=0x(x-18)+12(x-18)=0

(x-18)(x+12)=0x=-12,18

 



Q 4 :

If the vertices of a parallelogram PQRS taken in order are P(3, 4), Q(-2, 3) and R(-3, -2), then the coordinates of its fourth vertex S are

  • (-2, -1)

     

  • (-2, -3)

     

  • (2, -1)

     

  • (1, 2)

     

(3)

We know that the diagonals of a parallelogram bisect each other.

Therefore, midpoint of QS = midpoint of PR. Let the coordinate of S is (x, y)

(x-22,y+32)=(3-32,4-22)

x-22=3-32 and y+32=4-22

x-2=0  x=2

and y+3=2  y=-1

Hence, fourth vertex S are (2, -1).



Q 5 :

The centre of a circle is at (2, 0). If one end of a diameter is at (6, 0), then the other end is at :

  • (0, 0)

     

  • (4, 0)

     

  • (-2, 0)

     

  • (-6, 0)

     

(3)

(6+x2,0+y2)=(2,0)6+x2=2, 0+y2=0

⇒ x = –2 and y = 0

 



Q 6 :

XOYZ is a rectangle with vertices X(–3, 0), O(0, 0), Y(0, 4) and Z(x, y). The length of its each diagonal is

  • 5 units

     

  • 5 units

     

  • x2+y2 units

     

  • 4 units

     

(1)

We know that, Length of Diagonals are equal

In Rectangle, ZO = YX

ZO2=YX2(x-0)2+(y-0)2=(0+3)2+(4-0)2

x2+y2=25

x2+y2=5  Both diagonals are 5 units

 



Q 7 :

The point on x-axis which is equidistant from the points (5, – 3) and (4, 2) is :

  • (4.5, 0)

     

  • (7, 0)

     

  • (0.5, 0)

     

  • (– 7, 0)

     

(2)        (7, 0)

 



Q 8 :

PQ is a diameter of a circle with centre O(2, – 4). If the coordinates of the point P are (– 4, 5), then the coordinates of the point Q will be :

  • (– 3, 4.5)

     

  • (– 1, 0.5)

     

  • (4, – 5)

     

  • (8, – 13)

     

(4)       (8, – 13)

 



Q 9 :

Point P divides the line segment joining the points A(4, –5) and B(1, 2) in the ratio 5 : 2. Coordinates of point P are

  • (52,-32)

     

  • (112,0)

     

  • (137,0)

     

  • (0,137)

     

(3)           (137,0)

x=m1x2+m2x1m1+m2=5×1+2×45+2=5+87=137

y=m1y2+m2y1m1+m2=5×2+2×(-5)5+2=10-107=0



Q 10 :

If end points of a diameter of a circle are (-5,4) and (1,0), then the radius of the circle is:

  • 213units

     

  • 13units

     

  • 42units

     

  • 22units

     

(2)

Let given end points of diameter be A(-5,4) and B(1,0).

∴ Diameter has length, 

AB=(1+5)2+(0-4)2=36+16=52=213 unitsRadiusofcircle=2132=13units.