| 17. | Find the number of triangles in the given figure.
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Answer: Option C Explanation: The figure may be labelled as shown.
The simplest triangles are ABJ, ACJ, BDH, DHF, CIE and GIE i.e. 6 in number. The triangles composed of two components each are ABC, BDF, CEG, BHJ, JHK, JKI and CJI i.e. 7 in number. There is only one triangle JHI which is composed of four components. Thus, there are 6 + 7 + 1 = 14 triangles in the given figure. |
| 18. | Find the minimum number of straight lines required to make the given figure.
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Answer: Option B Explanation: The figure may be labelled as shown.
The horizontal lines are DE, FH, IL and BC i.e. 4 in number. The slanting lines are AC, DO, FN, IM, AB, EM and HN i.e. 7 in number. Thus, there are 4 + 7 = 11 straight lines in the figure. |
| 19. | Find the number of triangles in the given figure.
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Answer: Option D Explanation: The figure may be labelled as shown.
The simplest triangles are AJF, FBG, GCH, HDI and IEJ i.e. 5 in number. The triangles composed of three components each EBH, AIC, EFC, ADG and BJD i.e. 5 in number. Thus, there are 5 + 5 = 10 triangles in the figure. |
| 20. |
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Answer: Option C Explanation: The figure may be labelled as shown.
The simplest triangles are ABI, BIC, AIJ, CIJ, AHJ, CDJ, JHG, JDE, GJF and EJF i.e. 10 in number. The triangles composed of two components each are ABC, BCJ, ACJ, BAJ, AJG, CJE and GJE i.e. 7 in number. The triangles composed of four components each are ACG, ACE, CGE and AGE i.e. 4 in number. Total number of triangles in the figure =10+ 7 + 4 = 21. |
| 21. | Find the number of triangles in the given figure.
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Answer: Option D Explanation: The figure may be labelled as shown.
The simplest triangles are ABL, BCD, DEF, FGP, PGH, QHI, JQI, KRJ and LRK i.e. 9 in number. The triangles composed of two components each are OSG, SGQ, SPI, SRI, KSQ, KMS, FGH, JHI and JKL i.e. 9 in number. There is only one triangle i.e. KSG which is composed of four components. The triangles composed of five components each are NEI, ANI, MCG and KCO i.e. 4 in number. The triangles composed of six components each are GMK and KOG i.e. 2 in number. There is only one triangle i.e. AEI composed of ten components. There is only one triangle i.e. KCG composed of eleven components. Therefore, Total number of triangles in the given figure = 9 + 9+1 + 4 + 2+1 + 1 = 27. |
| 22. | Find the number of triangles in the given figure.
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Answer: Option A Explanation: The figure may be labelled as shown.
The simplest triangles are AGE, EGC, GFC, BGF, DGB and ADG i.e. 6 in number. The triangles composed of two components each are AGC, BGC and ABG i.e. 3 in number. The triangles composed of three components each are AFC, BEC, BDC, ABF, ABE and DAC i.e. 6 in number. There is only one triangle i.e. ABC composed of six components. Thus, there are 6 + 3 + 6 + 1 = 16 triangles in the given figure. |
| 23. | Find the number of triangles in the given figure.
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Answer: Option D Explanation: The figure may be labelled as shown.
The simplest triangles are ABF, BIC, CIH, GIH, FGE and AFE i.e. 6 in number. The triangles composed of two components each are ABE, AGE, BHF, BCH, CGH and BIE i.e. 6 in number. The triangles composed of three components each are ABH, BCE and CDE i.e. 3 in number. Hence, the total number of triangles in the figure = 6 + 6 + 3 = 15. |
| 24. |
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Answer: Option C Explanation: The figure may be labelled as shown.
The simplest triangles are AKI, AIL, EKD, LFB, DJC, BJC, DHC and BCG i.e. 8 in number. The triangles composed of two components each are AKL, ADJ, AJB and DBC i.e. 4 in number. The triangles composed of the three components each are ADC and ABC i.e. 2 in number. There is only one triangle i.e. ADB composed of four components. Thus, there are 8+ 4 + 2 + 1= 15 triangles in the figure. |
