Plane Geometry


  1. 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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    According to question , we draw a figure triangle ABC

    From right angle triangle , we have
    ∴ OB = √OA² + AB²
    OB = √12² + 5²
    OB = √144 + 25

    Correct Option: D

    According 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.


  1. 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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    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–similarity

    Correct Option: C

    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–similarity
    ∆ ABC ~ ∆ DBE
    From above it is clear that ∆ ABC and ∆ DBE are congruent triangles .



  1. 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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    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 ~ ∆ ABC

    Correct Option: D

    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 ~ ∆ ABC

    AP
    =
    PQ
    =
    2x
    =
    2
    = 2 : 3
    ABBC3x3


  1. 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









  1. 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 ~ ∆ABC

    Now,
    ☐ BDEC
    =
    1
    ∆ ADE1

    [DE divides ∆ into two equal parts]
    ☐ BDEC
    + 1 = 1 + 1
    ∆ ADE

    ∆ ABC
    = 2 =
    AB²
    ∆ ADEAD²

    AB
    = √2
    AD

    AB
    - 1 = √2 - 1
    AD

    BD
    = √2 - 1
    AD

    Correct Option: B

    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 ~ ∆ABC

    Now,
    ☐ BDEC
    =
    1
    ∆ ADE1

    [DE divides ∆ into two equal parts]
    ☐ BDEC
    + 1 = 1 + 1
    ∆ ADE

    ∆ ABC
    = 2 =
    AB²
    ∆ ADEAD²

    AB
    = √2
    AD

    AB
    - 1 = √2 - 1
    AD

    BD
    = √2 - 1
    AD

    AD
    =
    1
    BD2 - 1

    ∴ AD : BD = 1 : 2 √2



  1. 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









  1. 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
    DAEC

    Correct Option: D

    According to question , we draw a figure of triangle ABC

    Given , AB = 10 cm and AD = 4 cm
    DE || AC
    ∆ BDE ~ ∆ BAC

    BD
    =
    BE
    DAEC

    6
    =
    BE
    4EC

    ⇒ BE : CE = 3 : 2