OCR GCSE Mathematics Key Terms

A drawing on a flat, 2D surface that shows the length, width, and height of a solid object simultaneously.

The rule stating that two triangles are similar if all three of their corresponding angles are identical.

The mathematical principle that if two angles in a triangle are known to match another triangle, the third must also match due to the angles summing to 180 degrees.

A congruence criterion stating that two triangles are congruent if two pairs of corresponding angles and a non-included side are equal.

The actual number of occurrences (frequency) as opposed to a percentage or relative value.

The rate of change of velocity over time, calculated from the gradient of a velocity-time graph.

The difference between the final amount of an investment and the original principal.

The total amount of a quantity that has built up over time, represented graphically by the area under a rate-of-change graph.

The requirement in scale drawing to be within specific exam board tolerances, usually ±2 mm for length and ±2° for angles.

A technique used to factorise non-monic quadratics by finding two numbers that multiply to the product of 'a' and 'c' and sum to 'b'.

An angle that is strictly greater than 0° and less than 90°.

The process of calculating the total of two or more numbers.

The side of a right-angled triangle that is next to the specific interior angle being used but is not the hypotenuse.

Two angles that are side-by-side, sharing a common vertex and a common side (arm) without overlapping.

A fraction where the numerator, denominator, or both contain algebraic expressions.

The process of rearranging, expanding, simplifying, or factorising mathematical expressions to change their form.

A logical argument using generalized algebraic terms to show a mathematical statement is true for every possible value.

Another term for co-interior angles; they lie on the same side of the transversal and sum to 180 degrees.

Angles on opposite sides of a transversal between parallel lines, forming a 'Z-shape'; they are always equal.

The region of a circle located on the opposite side of a chord from the angle formed between that chord and a tangent.

A geometric rule stating that the angle between a tangent and a chord through the point of contact is equal to the angle subtended by the chord in the alternate segment.

The mathematical part of a formula, usually (-1)ⁿ, that causes the signs of terms to flip continuously.

Sequences where the signs of the consecutive terms alternate between positive and negative.

A situation in trigonometry where two different triangles can be formed from the same side-side-angle measurements, resulting in both an acute and an obtuse solution.

The maximum vertical distance from the center horizontal line of a wave to its peak or trough.

The angle formed at the centre of a circle by two radii, which is always twice the angle at the circumference subtended by the same arc.

A line that divides an angle into two perfectly equal parts, containing all points equidistant from the two intersecting lines.

The 90° angle formed when two chords are drawn from the endpoints of a diameter to any single point on the circumference.

The angle measured downwards from a horizontal line of sight to an object.

The angle measured upwards from a horizontal line of sight to an object.