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Tangent Problem

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Description:

Source(s):
Construct a circle with centre O. Mark a point P exterior to the circle. Construct the tangent lines to the circle going through point P. Describe the construction you have made.
Justify the correctness of your construction: Why is it correct? It is necessary to use geometric properties studied and accepted in the classroom.



Marrades R., Gutiérrez Á.
2000
 





Possible solutions

1. It is difficult to solve this problem if the way of connecting points O and P is not discovered (a circle with centre in the midpoint of OP; see Figure 24). This technique was unknown to the students, but they had studied, in activity 29, that any angle inscribed in a semicircle is a right angle, and this property was included in the list of accepted results. (Marrades R., Gutiérrez Á. 2000)
fig24
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