{"id":27704,"date":"2021-07-01T16:15:49","date_gmt":"2021-07-01T10:45:49","guid":{"rendered":"https:\/\/mcq-questions.com\/?p=27704"},"modified":"2022-03-02T10:31:03","modified_gmt":"2022-03-02T05:01:03","slug":"ncert-solutions-for-class-7-maths-chapter-7-ex-7-2","status":"publish","type":"post","link":"https:\/\/mcq-questions.com\/ncert-solutions-for-class-7-maths-chapter-7-ex-7-2\/","title":{"rendered":"NCERT Solutions for Class 7 Maths Chapter 7 Congruence of Triangles Ex 7.2"},"content":{"rendered":"
By SAS Congruence rule<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n
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Question 4. \nIn \u0394ABC, \u2220A =30\u00b0, \u2220B = 40\u00b0 and \u2220C= 110\u00b0 \nIn APQR, \u2220P = 30\u00b0, \u2220Q = 40\u00b0 and \u2220R = 110\u00b0 \nA Student says that \u0394ABC = \u0394PQR by AAA congruence criterion. Is he justified? Why or why not? \nAnswer: \nNo, he is not justified because AAA is not a congruence criterion.<\/p>\n
Question 5. \nIn the figure, the two triangles are congruent. The corresponding parts are marked. We can write \u0394RAT \u2245 ? \n \nAnswer: \nWe have N \u2194T \nO \u2194 A \nW \u2194 R \n\u2234 \u0394RAT \u2245 \u0394WON<\/p>\n
Question 6. \nComplete the congruence statement: \n\u0394BCA \u2245 ? \n \n\u0394QRS \u2245 ? \n \n(i) We have \nA \u2194 A \nB \u2194 B \nT \u2194 C \n\u2234 \u0394BCA \u2245 \u0394BTA<\/p>\n
(ii) We have \nR \u2194 P \nQ \u2194 T \nS \u2194 Q \n\u2234 \u0394QRS \u2245 \u0394TPQ<\/p>\n
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Question 7. \nIn a squared sheet, draw two triangles of equal areas such that \n(i) the triangles are congruent. \n(ii) the triangles are not congruent. \nWhat can you say about their perimeters? \nAnswer: \n \n(i) Area of \u0394ABC = \\(\\frac { 1 }{ 2 }\\) \u00d7 4 \u00d7 3 sq cm = 6 sq cm \nArea of \u0394CDE = = 6 sq cm \nPerimeter of \u0394ABC = (3 + 4 + 5) cm = 12 cm \nPerimeter of \u0394CDE = (3 + 4 + 5) cm = 12 cm \nThe two triangles are congruent. \n(\u2235 Perimeter of \u0394ABC = Perimeter of \u0394CDE) \n(ii) \n \nPerimeter of \u0394PQR = (3 + 4 + 5) cm = 12cm \nPerimeter of \u0394PRS = (4 + 3.5 + 4) cm = 11.5 cm \n\u2234 The two triangles are not congruent. \n(\u2235 Perimeter of \u0394PRS \u2260 Perimeter of \u0394PQR)<\/p>\n
Question 8. \nDraw a rough sketch of two triangles such that they have five pairs of congruent parts but still the triangles are not congruent. \nAnswer: \nIn \u0394ABC and \u0394DEF \n \nAB = 2 cm DF = 2cm \n\u2234 AB = DF \nBC = 4 cm, ED = 4 cm \n\u2234 BC = ED \nAC = 3 cm, EF = 3 cm \n\u2234 AC = EF \n\u2220BAC = \u2220EDF \n\u2220ABC = \u2220DEF \nBut \u0394ABC is not congruent to \u0394DEF.<\/p>\n
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Question 9. \nIf \u0394ABC and \u0394PQR are to be congruent, name one additional pair of corresponding parts. What criterion did you use? \n \nAnswer: \nGiven \u0394ABC = \u0394PQR \n\u2234 A \u2194 P; B \u2194 Q and C \u2194 R \nTwo angles \u2220B and \u2220C of \u0394ABC are respectively equal to two angles \u2220Q and \n\u2220R of \u0394PQR \nIf BC = QR then \u0394ABC \u2245 \u0394PQR (using ASA congruence criterion) \nWe use ASA congruence criterion.<\/p>\n
Question 10. \nExplain why AABC = AFED \n \nAnswer: \nZB = ZE (each 90\u00b0) \nZA = ZF (Given) \nZC = ZD \n(3<sup>rd<\/sup> angle are equal) BC = ED (Given) \nTwo angles ZB and ZC and included side BC of AABC are respectively equal to the angle ZE and ZD and the included side ED of ADEF. \n\u2234 \u0394ABC \u2245 \u0394FED (ASA)<\/p>\n","protected":false},"excerpt":{"rendered":"
These NCERT Solutions for Class 7 Maths Chapter 7 Congruence of Triangles Ex 7.2 Questions and Answers are prepared by our highly skilled subject experts. NCERT Solutions for Class 7 Maths Chapter 7 Congruence of Triangles Exercise 7.2 Question 1. Which congruence criterion do you use in the following? (a) Given : AC = DF …<\/p>\n