2
Two triangles are congruent if they are both
the same size and shape.
For Example
6cm 6cm
8cm 8cm
70
o
70
o
7cm 7cm
75
o
75
o
35
o
35
o
3
Two triangles are congruent if.
All the three Sides of the triangles
are equal in length.
SSS
6cm 6cm
8cm 8cm
7cm 7cm
4
Two triangles are congruent if.
Two pairs of corresponding Sides
and the included Angle are equal.
SAS
6cm 6cm
8cm 8cm
70
o
70
o
5
Two triangles are congruent if.
Two pairs of Angles and any pair of
corresponding Sides are equal.
AAS
8cm 8cm
70
o
70
o
75
o
75
o
6
Two triangles are congruent if.
Both have a Right angle. The Hypotenuses and
one pair of corresponding Sides are equal.
RHS
8cm
7cm
8cm
7cm
7
Example 1
A
B
C
10cm
3.4cm
9.4cm
P
Q
R
10cm
3.4cm
9.4cm
AB = PQ (Corresponding Sides)
BC = QR (Corresponding Sides)
AC = PR (Corresponding Sides)
Therefore Congruent by SSS
8
Example 2
A
B
C
3.4cm
9.4cm
P
Q
R
3.4cm
9.4cm
AB = PQ (Corresponding Sides)
BC = QR (Corresponding Sides)
ÐB = ÐQ (Included angle)
Therefore Congruent by SAS
9
Example 3
A
B
C
10cm
70
o
20
o
P
Q
R
10cm
70
o
20
o
ÐA = ÐP (Corresponding Angles)
ÐC = ÐR (Corresponding Angles)
AC = PR (Corresponding Sides)
Therefore Congruent by AAS
10
Example 4
A
B
C
10cm
3.4cm
P
Q
R
10cm
3.4cm
ÐB = ÐQ = 90
o
(Right Angle)
AC = PR (Hypotenuse)
BC = QR (Corresponding Sides)
Therefore Congruent by RHS