Plane Geometry
-  A ship after sailing 12 km towards south from a particular place covered 5 km more towards east. Then the straightway distance of the ship from that place is
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                        View Hint View Answer Discuss in Forum According to question , we draw a figure triangle ABC  
 From right angle triangle , we have
 ∴ OB = √OA² + AB²
 OB = √12² + 5²
 OB = √144 + 25Correct Option: DAccording to question , we draw a figure triangle ABC  
 From right angle triangle , we have
 ∴ OB = √OA² + AB²
 OB = √12² + 5²
 OB = √144 + 25
 OB = √169 = 13 km.
-  In ∆ ABC, two points D and E are taken on the lines AB and BC respectively in such a way that AC is parallel to DE. Then ∆ ABC and ∆ DBE are
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                        View Hint View Answer Discuss in Forum According to question , we draw a figure triangle ABC in which two points D and E are taken on the lines AB and BC respectively in such a way that AC is parallel to DE ,  
 In ∆ ABC and ∆ DBE,
 DE || AC
 ∴ ∠BAC = ∠BDE
 ∠BCA = ∠BED
 ∴ By AA–similarityCorrect Option: CAccording to question , we draw a figure triangle ABC in which two points D and E are taken on the lines AB and BC respectively in such a way that AC is parallel to DE ,  
 In ∆ ABC and ∆ DBE,
 DE || AC
 ∴ ∠BAC = ∠BDE
 ∠BCA = ∠BED
 ∴ By AA–similarity
 ∆ ABC ~ ∆ DBE
 From above it is clear that ∆ ABC and ∆ DBE are congruent triangles .
-  Inside a triangle ABC, a straight line parallel to BC intersects AB and AC at the point P and Q respectively. If AB = 3 PB, then PQ : BC is
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                        View Hint View Answer Discuss in Forum As per the given in question , we draw a figure triangle ABC  
 Let PB = x ⇒ AB = 3x and AP = 3x – x = 2x
 In ∆ ABC, PQ || BC
 ⇒ ∆ APQ ~ ∆ ABCCorrect Option: DAs per the given in question , we draw a figure triangle ABC  
 Let PB = x ⇒ AB = 3x and AP = 3x – x = 2x
 In ∆ ABC, PQ || BC
 ⇒ ∆ APQ ~ ∆ ABC⇒ AP = PQ = 2x = 2 = 2 : 3 AB BC 3x 3 
 
-  In ∆ ABC, D and E are points on AB and AC respectively such that DE || BC and DE divides the ∆ ABC into two parts of equal areas. Then ratio of AD and BD is
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                        View Hint View Answer Discuss in Forum On the basis of question we draw a figure of triangle ABC in which D and E are points on AB and AC respectively such that DE || BC ,  
 DE ||BC
 ∠ADE = ∠ABC
 ∠AED = ∠ACB
 ∴ ∆ADE ~ ∆ABCNow, ☐ BDEC = 1 ∆ ADE 1 
 [DE divides ∆ into two equal parts]⇒ ☐ BDEC + 1 = 1 + 1 ∆ ADE ⇒ ∆ ABC = 2 = AB² ∆ ADE AD² ⇒ AB = √2 AD ⇒ AB - 1 = √2 - 1 AD ⇒ BD = √2 - 1 AD 
 Correct Option: BOn the basis of question we draw a figure of triangle ABC in which D and E are points on AB and AC respectively such that DE || BC ,  
 DE ||BC
 ∠ADE = ∠ABC
 ∠AED = ∠ACB
 ∴ ∆ADE ~ ∆ABCNow, ☐ BDEC = 1 ∆ ADE 1 
 [DE divides ∆ into two equal parts]⇒ ☐ BDEC + 1 = 1 + 1 ∆ ADE ⇒ ∆ ABC = 2 = AB² ∆ ADE AD² ⇒ AB = √2 AD ⇒ AB - 1 = √2 - 1 AD ⇒ BD = √2 - 1 AD ⇒ AD = 1 BD √2 - 1 
 ∴ AD : BD = 1 : 2 √2
-  In ∆ ABC, DE || AC. D and E are two points on AB and CB respectively. If AB = 10 cm and AD = 4 cm, then BE : CE is
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                        View Hint View Answer Discuss in Forum According to question , we draw a figure of triangle ABC  
 Given , AB = 10 cm and AD = 4 cm
 DE || AC
 ∆ BDE ~ ∆ BAC⇒ BD = BE DA EC 
 Correct Option: DAccording to question , we draw a figure of triangle ABC  
 Given , AB = 10 cm and AD = 4 cm
 DE || AC
 ∆ BDE ~ ∆ BAC⇒ BD = BE DA EC ⇒ 6 = BE 4 EC 
 ⇒ BE : CE = 3 : 2
 
	