Filters

Sort by :
Q

1.(v) Find the remainder when$x^ 3 + 3x^ 2 + 3x + 1$ is divided by
(v)   $5+2x$

5+2x

Q. 2.     Discuss :

(a) Is garbage disposal the responsibility only of the government?

No, garbage disposal is not only the responsibility of the government.It is the responsibility of the citizens as well. It is one's duty to keep the environment clean. The people should throw garbage at proper place. Moreover, we should start recycling waste.

Q. 1    (b) Have you seen any other organism besides redworms, in your pit? If yes, try to find out their names. Draw pictures of these.

Yes, a pit contains other organisms such as beetles, spiders and oter types of earthworm. Moreover it contains microscopic bacteria.

Q. 1.     (a) Which kind of garbage is not converted into compost by the redworms?

Non-biodegradable wastes are not converted into compost by the red worms. Example: Plastic bags, plastics, aluminium foil, etc.

6. In Fig. 6.44, the side QR of $\Delta$ PQR is produced to a point S. If the bisectors of $\angle$ PQR and $\angle$ PRS meet at point T, then prove that  $\angle$ QTR = $\frac{1}{2}$   $\angle$QPR.

We have,  PQR is produced to a point S and  bisectors of PQR and PRS meet at point T, By exterior angle sum property, PRS = P + PQR Now,  ................(i) Since QT and QR are the bisectors of  PQR and PRS respectively. Now, in QRT, ..............(ii) From eq (i) and eq (ii),  we get Hence proved

5. In Fig. 6.43, if PQ $\bot$ PS, PQ $||$SR, $\angle$ SQR = 28° and $\angle$ QRT = 65°, then find the values of x and y.

We have,  PQ PS, PQ || SR, SQR = 28° and QRT = 65° Now, In  QRS, the side SR produced to T and PQ || RS therefore, QRT =  =   So,  Also, QRT = RSQ + SQR (By exterior angle property of a triangle) Therefore, RSQ = QRT - SQR                     Now, in  PQS, P + PQS + PSQ =

4. In Fig. 6.42, if lines PQ and RS intersect at point T, such that $\angle$ PRT = 40°, $\angle$ RPT = 95° and $\angle$ TSQ = 75°, find $\angle$ SQT.

We have, lines PQ and RS intersect at point T, such that PRT = 40°, RPT = 95° and TSQ = 75° In PRT, by using angle sum property PRT + PTR + TPR =  So, PTR  =     Since lines, PQ and RS intersect at point T therefore, PTR = QTS (Vertically opposite angles)                 QTS =  Now, in QTS, By using angle sum property TSQ + STQ + SQT =  So, SQT =

3.   In Fig. 6.41, if AB $||$ DE, $\angle$ BAC = 35° and $\angle$ CDE = 53°, find $\angle$ DCE.

We have,  AB || DE,  BAC = 35° and  CDE = 53° AE is a transversal so,  BAC =  AED =  Now, In  CDE, CDE + DEC + ECD =  (By angle sum property) Therefore, ECD =

2. In Fig. 6.40, $\angle$ X = 62°, $\angle$ XYZ = 54°. If YO and ZO are the bisectors of $\angle$ XYZ and $\angle$ XZY respectively of $\Delta$ XYZ, find $\angle$ OZY and $\angle$ YOZ.

We have  X = , XYZ =  YO and ZO bisects the XYZ and XZY Now, In XYZ, by using angle sum property XYZ + YZX + ZXY =  So, YZX =        YZX =  and, OYZ =  also, OZY =  Now, in OYZ  Y + O + Z =   [Y =  and Z = ] So, YOZ =

1. In Fig. 6.39, sides QP and RQ of $\Delta$PQR are produced to points S and T respectively. If $\angle$ SPR = 135° and $\angle$ PQT = 110°, find $\angle$ PRQ.

Given, PQR is a triangle, SPR =,  PQT =  Now, TQP + PQR =  (Linear pair) So, PQR =  Since the side of QP of the triangle, PQR is produced to S So, PQR + PRQ =  (Exterior angle property of triangle)

6.  In Fig. 6.33, PQ and RS are two mirrors placed parallel to each other. An incident ray AB strikes the mirror PQ at B, the reflected ray moves along the path BC and strikes the mirror RS at C and again reflects back along CD. Prove that AB $||$ CD.

Draw  a ray BL PQ and CM  RS Since PQ || RS (Given) So, BL || CM and BC is a transversal  LBC =  MCB (Alternate interior angles).............(i) It is known that, angle of incidence  = angle of reflection So, ABL = LBC and MCB =  MCD ..................(ii) Adding eq (i) and eq (ii), we get ABC = DCB Both the interior angles are equal Hence AB || CD

5.  In Fig. 6.32, if AB $||$ CD, $\angle$ APQ = 50° and $\angle$ PRD = 127°, find x and y.

Given, AB || CD, APQ =  and PRD =  PQ is a transversal. So,  APQ = PQR=  (alternate interior angles) Again, PR is a transversal. So,  y + =  (Alternate interior angles)

4.  In Fig. 6.31, if PQ $||$ ST, $\angle$ PQR = 110° and $\angle$ RST = 130°, find $\angle$ QRS.
[Hint : Draw a line parallel to ST through point R.]

Draw a line EF parallel to the ST through R. Since PQ || ST and ST || EF   EF || PQ PQR = QRF =   (Alternate interior angles) QRF = QRS + SRF .............(i) Again, RST + SRF =  (Interior angles of two parallels ST and RF)   (RST = , given) Thus, QRS =

3.  In Fig. 6.30, if AB $||$ CD, EF $\bot$ CD and $\angle$ GED = 126°, find $\angle$ AGE, $\angle$ GEF and $\angle$ FGE.

Given AB || CD, EFCD and GED =  In the above figure,  GE is transversal. So, that AGE = GED =   [Alternate interior angles] Also, GEF = GED - FED                       =            Since AB is a straight line  Therefore, AGE  + FGE =   So, FGE =

2. In Fig. 6.29, if AB $||$ CD, CD $||$ EF and y : z = 3 : 7, find x.

Given AB || CD and CD || EF and  therefore, AB || EF and  (alternate interior angles)..............(i) Again, CD || AB  .............(ii) Put the value of  in equation (ii), we get Then  By equation (i), we get the value of

1. In Fig. 6.28, find the values of x and y and then show that AB $||$ CD.

Given that, In the figure, CD and PQ intersect at  F Therefore,   (vertically opposite angles) PQ is a straight line. So,  Hence AB || CD (since  and are  alternate interior angles)

6. It is given that $\angle$ XYZ = 64° and XY is produced to point P. Draw a figure from the given information. If ray YQ bisects $\angle$ ZYP, find $\angle$ XYQ and reflex $\angle$ QYP.

Given that, XYZ =  and XY produced to point P and Ray YQ bisects ZYP   Now, XYP is a straight line So, XYZ + ZYQ + QYP =  Thus reflex of QYP =  Since XYQ = XYZ + ZYQ  [      =

5. In Fig. 6.17, POQ is a line. Ray OR is perpendicular to line PQ. OS is another ray lying between rays OP and OR. Prove that    $\angle \textup{ROS} = \frac{1}{2}(\angle \textup{QOS} - \angle \textup{POS})$

Given that, POQ is a line, OR  PQ and  ROQ is a right angle. Now,  POS + ROS +  ROQ =   [since POQ is a straight line]  .............(i) and,  ROS +  ROQ =  QOS        ..............(ii) Add the eq (i ) and eq (ii),  we get hence proved

4. In Fig. 6.16, if x + y = w + z, then prove that AOB is a line.

Given that,  ..............(i) It is known that, the sum of all the angles at a point =    ..............(ii) From eq (i) and eq (ii), we get Hence proved AOB is a line.

3.  In Fig. 6.15, $\angle$ PQR = $\angle$ PRQ, then prove that $\angle$ PQS = $\angle$ PRT.

Given that, ABC is a triangle such that  PQR =  PRQ  and ST is a straight line. Now,  PQR +  PQS =      {Linear pair}............(i) Similarly,  PRQ +  PRT = ..................(ii) equating the eq (i) and eq (ii), we get    {but  PQR =  PRQ } Therefore,  PQS = PRT Hence proved.
Exams
Articles
Questions