**Congurency:**

Two geometric figures are congurent, if they are of the same shape and size.

AB =XY ∠a = ∠x

BC = YZ ∠b = ∠y

AC = XZ ∠c = ∠z

**Tests of Congurency:**

- Side Side Side (SSS) – all sides are equal
- Angle Angle Angle (AAA) – all angles are same
- Side Angle Side (SAS) – two sides and one angle are equal
- Right Angled – Hypotenuse – Side – one right angle and hyp & side equal

≡ – To denote “ is congruent to”

≢ – To denote “ is not congruent to”

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**Similarity:**

When two figures are similar, they are exactl the same in shape but not in size.

**Test:**

- Equal corresponding Angles:

The angles of one triangle are equal to corresponding angles of the other triangle.

- Proportional Corresponding Angles.
- Two Pairs of Proportional Corresponding Sides with equal angles.

We right similarity as** ( **~ ) i.e ΔABC ~ ΔDEF

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