Thursday, October 7, 2010

Angle PSLE 2010 P2 Q13

In the figure below, ABC is a triangle. X, Y and Z are points on the triangle such that AX=AY and YB=ZB.














If angle AYZ=104⁰ and angle XYB=107⁰, find angle ZCX.



180  -  104  =  76

180  -  76  -  76  =  38


180  -  107  =  73

180  -  73  -  73  =  34

180  -  28  -  34  =  118⁰

It is  118°.



Alternative solution provided by P6 pupil

107° + 104°  =  211°

211°  -  180°  =  31°

360°  -  31°  -  107°  -  104°  =  118°

2 comments:

  1. As appeared in PSLE 2010 exam:

    In the figure below, ABC is a triangle. X, Y and Z are points on the triangle such that AX=AY and YB=ZB.
    If angle AYZ=104⁰ and angle XYB=107⁰, find angle ZCX.

    Diagram given:
    ABC is a triangle with A at the left hand corner and goes clockwise passing B, C and back to A. CB is the base.
    X is a point along line AC and is joined to a point Y which is along the line AB.
    Z is a point along CB and is joined to point Y.
    Both AX and AY are marked as equal in length.
    Both YB and BZ are marked as equal in length.

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  2. 180-107=73
    180-104=76
    180-73=107
    180-76=104
    180-76-73=31
    Total angles in a 4sided figure equals to 360 degrees
    360-104-107-31=118

    ReplyDelete