Year 10 Congruence, Similarity, and Enlargement

Vocabulary flashcards covering key definitions, angle rules in parallel lines, and congruence and similarity conditions from the Year 10 mathematics unit.

Enlarge

To make a shape bigger (or smaller) by a given multiplier (scale factor).

Scale Factor

The multiplier of enlargement, representing the multiplicative relationship between two lengths.

Centre of Enlargement

The point the shape is enlarged from.

Similar

When one shape can become another with a reflection, rotation, enlargement, or translation.

Congruent

Shapes that are identical, having the exact same size and shape (all corresponding sides and angles are the same size).

Corresponding

Items that appear in the same place in two similar situations.

Parallel

Straight lines that never meet and have equal gradients.

Fractional Scale Factor

A scale factor less than $1$ that makes a shape smaller.

Alternate Angles

Angles between parallel lines that are equal and the same size.

Corresponding Angles

Angles in matching relative positions along parallel lines that are equal and the same size.

Co-interior Angles

Angles between parallel lines on the same side of a transversal that have a sum of $180^\circ$.

Side-Side-Side (SSS)

A condition for triangle congruence where all three sides on the triangle are the same size.

Angle-Side-Angle (ASA)

A condition for triangle congruence where two angles and the side connecting them are equal in two triangles.

Side-Angle-Side (SAS)

A condition for triangle congruence where two sides and the angle in-between them are equal in two triangles (meaning the third side is also the same size on both shapes).

Right Angle-Hypotenuse-Side (RHS)

A condition for triangle congruence where both triangles have a right angle, and the hypotenuse and one side are the same.

Vertically Opposite Angles

Angles opposite each other when two lines cross, which are equal and can be used to demonstrate that two triangles are similar.