Year 7 Mathematics Accelerated - Topic 8: Angles, Geometry and Pythagoras' Theorem

Vocabulary flashcards covering key terms from Topic 8: Angles, Geometry and Pythagoras' Theorem (Year 7 Accelerated).

Point

A location in space that has no length or width; represented by a dot labelled with a capital letter.

Interval

A line joining two points; named using a bar over the end labels.

Ray

A part of a line that starts at a point and extends to infinity in one direction; named with an arrow indicating direction.

Line

A straight path that extends to infinity in both directions; named with a double-headed arrow.

Perpendicular lines

Two lines that meet to form a right angle; symbol ⟂.

Parallel lines

Two lines that never meet and have the same slope; symbol ∥; labeled with matching arrowheads.

Vertex

The common endpoint of two rays that form an angle.

Arm

One of the rays that form an angle.

Angle

The amount of rotation from one arm to the other at a common vertex, measured in degrees.

Acute angle

An angle between 0° and 90°.

Right angle

An angle of exactly 90°, usually marked by a small square.

Obtuse angle

An angle between 90° and 180°.

Straight angle

An angle of exactly 180°, formed by a straight line.

Reflex angle

An angle between 180° and 360°.

Complementary angles

Two angles whose measures add to 90°.

Supplementary angles

Two angles whose measures add to 180°.

Vertically opposite angles

When two straight lines cross, opposite angles are equal.

Transversal

A line that crosses two or more lines.

Alternate angles (Zangles)

Angles on alternate sides of a transversal formed by two parallel lines; equal when the lines are parallel.

Corresponding angles (Fangles)

Angles in corresponding positions on a transversal with parallel lines; equal.

Cointerior angles (Cangles)

Interior angles on the same side of a transversal; sum to 180°.

Exterior angle

An angle formed outside a triangle by extending a side; equals the sum of the two interior opposite angles.

Interior angle sum of a triangle

The interior angles of any triangle add up to 180°.

Sum around a point

Angles around a common point add up to 360°.

Quadrilateral

A polygon with four sides.

Triangle

A polygon with three sides.

Hypotenuse

The side opposite the right angle in a right-angled triangle; the longest side.

Pythagoras' theorem

In a right-angled triangle, a^2 + b^2 = c^2, where c is the hypotenuse.

Pythagorean triad

Three positive integers a, b, c that satisfy a^2 + b^2 = c^2.

Euclid's formula (Pythagorean triples)

For integers p>q>0, the triple {p^2−q^2, 2pq, p^2+q^2} is a Pythagorean triple.

Isosceles triangle

A triangle with two equal sides.

Equilateral triangle

A triangle with all three sides equal; all angles are 60°.

Scalene triangle

A triangle with all three sides of different lengths.

Rectangle

A parallelogram with all angles equal to 90°.

Square

A rectangle with all sides equal and all angles 90°.

Rhombus

A parallelogram with all sides equal; diagonals bisect angles.

Parallelogram

A quadrilateral with opposite sides parallel and equal; opposite angles are equal.

Kite

A quadrilateral with two pairs of equal adjacent sides; diagonals are perpendicular.

Trapezium

A quadrilateral with at least one pair of parallel sides.

Quadrilateral angle sum

The interior angles of a quadrilateral add to 360°.