# Basic math glossary-R

Basic math glossary-R define words beginning with the letter R

Radius: The distance from the center of a circle to the edge of a circle.

Rate: Rate means percent.

Rate of commission: A percent used to calculate the commission.

Rate of interest: A percent charged when borrowing money.

Ratio: The comparison of two numbers using division

Ray: A line with a beginning point but no endpoint.

Real distance: As opposed to distance on a map, it is the actual distance between two locations.

Rectangle: A parallelogram with four right angles.

Rectangular prism: A prism that has rectangular faces

Reflex angle: An angle whose measure is bigger than 180 degrees, but less than 360 degrees.

Remainder: The amount left over when a number does not divide another number evenly.

Rectangle: A parallelogram with four right angles.

Repeating decimal: A decimal where the same series of digits repeat

Rhombus: A parallelogram with four equal sides and opposite angles that are equal.

Right angle: An angle whose measure is 90 degrees.

Right triangle: A triangle with one right angle.

Rhombus: A parallelogram with four equal sides and opposite angles that are equal.

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