ABSTRACT
A side view is shown in Figure 5.4 where AF is the minimum length of ladder. Since BD and CF are parallel, ADB DFE (corresponding angles between parallel lines). Hence triangles BAD and EDF are similar since their angles are the same. AB AC BC AC DE 5.5 3 2.5 m
By proportion:
AB DE
BD EF
i.e. EF
2 5 3
9. Congruent triangles – two triangles are congruent if: (i) the three sides of one are equal to the three sides of the
other, (ii) they have two sides of the one equal to two sides of
the other, and if the angles included by these sides are equal,
(iii) two angles of the one are equal to two angles of the other and any side of the first is equal to the corresponding side of the other, or
(iv) their hypotenuses are equal and if one other side of one is equal to the corresponding side of the other.
