Page 29 - Mathematics_Form_Two

Congruence

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(b) If CAB = BEP, prove that and QPR. Therefore, ABC = PQR,
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BDE = ACB. BCA = QRP, and BAC QPR.= ˆ
Postulates for congruence of triangles
Congruence of triangles Three conditions for congruence are
FOR ONLINE READING ONLY
Two triangles ABC and PQR are said to be sufficient to prove that two triangles
congruent if pairs of corresponding sides are congruent. The postulates that are
are equal and pairs of corresponding angles commonly used include the Side-Side-
are equal. This fact is mathematically Side (SSS), Side-Angle-Side (SAS),
represented as ∆ABC ≅ ∆PQR. The Angle-Angle-Side (AAS), and Right Mathematics for Secondary Schools
symbol ≅ means "congruent to".
angle-Hypotenuse-Side (RHS).
Consider the triangle in Figure 2.1.
Side-Side-Side (SSS) postulate

The SSS postulate states that two
triangles are congruent if the pairs of
their corresponding sides are equal. The
postulate is illustrated in Figure 2.2.

Figure 2�1: Conguerence of triangles

From Figure 2.1, if ∆ ABC ≅∆ PQR ,
the pairs of corresponding sides are AB = PQ,
and
and
and PQ, BC = QR,
AC = PR.
AB = BC = QR, and AC = PR.
Therefore, AB = PQ, BC = QR, and
AC = PR.
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Pairs of corresponding angles are ABC Figure 2�2: Pair of congruent triangles
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and PQR, BCA and QRP, and BAC satifying SSS postulate.
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Student's Book Form Two

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