Theorem: The diagonal of a rhombus are perpendicular to each other | |
Given: A rhombus ABCD in which AC and BD are diagonals. To Prove: AC and BC intersect perpendicularly. Proof: As ABCD is a rhombus Therefore it is a parallelogram AB= BC = CD= DA and AB ||CD , AD||BC ....................(1) Also diagonals of a parallelogram bisect each other. AO = OC and BO = OD ...................(2) In BOC and COD BO = DO [ From Equation (2)] BC = CD [ From Equation (1)] OC = OC [ Common ] Therfore BOC DOC [SSS Criteria of Congruence] [ By CPCT ] ............(3) But [Linear Pair] [Using Eq 3]
Similarly we can prove that Hence Proved. | |
Theorem: Show that if the diagonals of a quadrilateral bisect each other at right angles, then it is a rhombus. | |
Given: A quadrilateral ABCD such that AC and CD bisect at Right angle. AO = OC and BO = OD ....................(1) AC BD To Prove: ABCD is a rhombus. Proof: In AOB and COD AO = OC [ From Equation (1)] BO = OD [ From Equation (1)] AOB = COD [ Each as AC BD] Therefore AOB COD [ SAS Criteria of Congurence] BAO = DCO [CPCT] But they are alternate angles When AB and CD are straight lines and AC is the transversal AB || CD Similarly we can Prove that AD || BC As both pairs of opposite sides are equal Therefore ABCD is a ||gm In AOB and COB AO = OC [ From Equation (1)] BO = OB [ Common] AOB = COB [ Each as AC BD] Therefore AOB COB [ SAS Criteria of Congurence] AB = BC [CPCT] As ABCD is a IIgm and the adjacent sides are equal AB = BC Therefore ABCD is a rhombus | |
Illustration: ABCD is a rhombus in which diagonal AC is produced to E . If find | |
Solution: As ABCD is a rhombus and we know diagonals of rhombus bisect at right angle. In [Exterior angle = Sum of Interior Opposite Angles] As every rhombus is a parallelogram, Therefore CD || AB [Alternate Interior Angles when CD || AB and BD is the transversal] In the figure [Linear pairs when ACE is a ray and DC stands on it ] In [ Angles opposite to equal sides are equal and AD = DC sides of a rhombus] Hence |
My experience was very good with Abhyas academy. I am studying here from 6th class and I am satisfied by its results in my life. I improved a lot here ahead of school syllabus.
Abhyas is a complete education Institute. Here extreme care is taken by teacher with the help of regular exam. Extra classes also conducted by the institute, if the student is weak.
I have spent a wonderful time in Abhyas academy. It has made my reasoning more apt, English more stronger and Maths an interesting subject for me. It has given me a habbit of self studying
A marvelous experience with Abhyas. I am glad to share that my ward has achieved more than enough at the Ambala ABHYAS centre. Years have passed on and more and more he has gained. May the centre flourish and develop day by day by the grace of God.
My experience with Abhyas is very good. I have learnt many things here like vedic maths and reasoning also. Teachers here first take our doubts and then there are assignments to verify our weak points.
About Abhyas metholodology the teachers are very nice and hardworking toward students.The Centre Head Mrs Anu Sethi is also a brilliant teacher.Abhyas has taught me how to overcome problems and has always taken my doubts and suppoeted me.
One of the best institutes to develope a child interest in studies.Provides SST and English knowledge also unlike other institutes. Teachers are co operative and friendly online tests andPPT develope practical knowledge also.
It was good as the experience because as we had come here we had been improved in a such envirnment created here.Extra is taught which is beneficial for future.
Being a parent, I saw my daughter improvement in her studies by seeing a good result in all day to day compititive exam TMO, NSO, IEO etc and as well as studies. I have got a fruitful result from my daughter.
It was a good experience with Abhyas Academy. I even faced problems in starting but slowly and steadily overcomed. Especially reasoning classes helped me a lot.