Q.1. P and R are point on side CD of a parallelogram ABCD . Show that (i). ar (triangle PAB) = ar(triangle RAB) (ii). aIf ar (triangle PAB) = 8 cm square, find ar (ABCD) Q.2. Prove that equal chords of two congruent circles subtend equal angles at their centers . Q.3. Construct a square whose each side measure 5 cm . Q.4. ABCD is a parallelogram in which diagonal BD bisects angle B . Show that BD bisects angle D also . Q.5. A 4 cm wooden cube is cut into 1 cm cubes . What is the percentage increase in the surface area after such cutting ?

2
Ok bhaiya
for earn point delete your account and make another account
Why
bcz after making another account u will 50 free points
hey why so many questions in single thread ?

Answers

2015-04-15T13:59:52+05:30
Q1 : 

\triangle PAB and \triangle RAB have same base AB.
Since they lie between parallel sides, the height is also same.
Consequently areas will be same.
1 1 1
2015-04-15T19:47:48+05:30

This Is a Certified Answer

×
Certified answers contain reliable, trustworthy information vouched for by a hand-picked team of experts. Brainly has millions of high quality answers, all of them carefully moderated by our most trusted community members, but certified answers are the finest of the finest.
See diagram.

Take AB as the base of the parallelogram.
Then  draw perpendiculars from P and R on to AB.  Since  AB || CD,  the two perpendiculars are parallel and equal to the altitude of the parallelogram with AB as the base.

 The area of triangle PAB = area of RAB = 1/2 * AB * altitude.
  Area of parallelogram ABCD =  AB * altitude  = twice that of the triangles.
                       =  16 cmsquare.
==========================
see diagram.
   Take a circle of radius R.  Two congruent circles mean that their radii are same.  So we can work with one circle itself.    So I draw two chords AB and DE  of equal length L.  C is the center of circle.
    
  Look at the triangles CAB and CDE.  The sides  AB = DE, given.  Then CA = CB = CD = CE = radius of the triangle.  Hence the two triangles are congruent.  Hence angles  ACB and angle DCE are same.  So the angles subtended are same.
=======================
3.
     Draw a line horizontally in the middle of paper sheet, and measure 5 cm using a ruler.  Mark the end points as A and B.  Now using the perpendicular bisector method using compass or by using protractor draw a line AD at A and  a line BC at B , both perpendicular to the line AB.  Use the ruler or the compass measuring 5 cm, to cut off these BC and AD at 5 cm.  Now join CD.   
you have the square.
=============================
4  In parallelogram ABCD, the diagonal BD bisects angle B.  Means that
         angle ABD = angle DBC.
   AD || BC.  and BD is a transversal line cutting the two parallel lines.
   Hence,  we have  angle ADB = angle DBC  as they are alternate angles.
                             also angle ABD = angle BDC  as they are  alternate angles.
             Since angle ABD = angle DBC, the other two angles ADB = angle BDC.
   So BD bisects  angle D also.
====================
5

cube edge length = 4 cm
its total  surface are a =  6 * 4²  = 96 cm²

volume of the cube = 4³ = 64 cm³
volume of small cubes  =  1³ cm³
number of small cubes made from the big cube :  64 cm³/1 cm³ = 64
surface area of all 64 small cubes : 64 * 6 * 1² = 384 cm²

increase in surface area =  384 - 96 = 288 cm²
% increase =  288/96 * 100 =  300%


1 5 1