Parallel, Perpendicular, Polygon

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This is the Math Dictionary words that start with P for words like: parallel, perpendicular, and perimeter. Parallel is easier for kids to remember once you make the association that the double l toward the middle is a set of parallel lines.

**P.M.** - the period of time between noon to just before midnight.

**Palindrome** - words, numbers and phrases that can be read the same backwards as forwards. (racecar, 1221)

**Palindromic** - a positive integer is said to be palindromic with respect to a base b if its representation in base b reads the same from left to right as from right to left.

**Pandigital** - a decimal integer is called pandigital if it contains each of the digits from 0 to 9.

**Paraboloid** - a paraboloid of revolution is a surface of revolution produced by rotating a parabola about its axis.

**Paradox** - a statement that appears to contradict itself.

**Parallel** - lines that are in the same plane that do not intersect.

**Parallel Straight Lines** - those which have the same direction.

**Parallelepiped** - a prism whose bases are parallelograms.

**Parallelogram** - a quadrilateral that contains two pairs of parallel sides.

**Parallelopipedon** - a prism having parallelograms for its bases.

**Parentheses** - the symbols ( and ) used for grouping expressions.

**Partnership** - the association of two or more persons in business, who unite their capital and services, and share the gains or losses according to a stipulated agreement.

**Pascal’s Triangle** - a triangular array of binomial coefficients.

**Pattern** - characteristic(s) observed in one item that may be repeated in similar or identical manners in other items.

**Pedal Triangle** - the pedal triangle of a point P with respect to a triangle ABC is the triangle whose vertices are the feet of the perpendiculars dropped from P to the sides of triangle ABC.

**Pentagon** - a five sided polygon.

**Pentagonal Number** - a number of the form n(3n-1)/2.

**Pentomino** - a five-square polyomino.

**Percent** - hundredths, a ratio that compares a number to one hundred. The symbol for percent is %, (cent = 1/100).

**Perfect Cube** - an integer is a perfect cube if it is of the form m3 where m is the integer, (m x m x m), (m)(m)(m).

**Perfect Number** - a positive integer that is equal to the sum of its proper divisors. For example, 28 is perfect because 28=1+2+4+7+14.

**Perfect Power** - a number which is the product of equal factors.

**Perfect Square** - an integer of the form m2 where m is an integer, (m x m), (m)(m).

**Perimeter** - the sum of the lengths of all the sides of a polygon, quadrangle s+s+s+s=p.

**Permutation** - a particular ordering of a set of objects, an arrangement of objects.

**Perpendicular** - two straight lines are said to be perpendicular if they meet at right angles.

**Personal View** - an approach taken by mathematicians and philosophers to calculate probability.

**Pi** - the ratio of the circumference to the diameter.(3.14)

**Pictograph** - a graph that uses symbols to represent data.

**Pie Chart** - a type of chart in which a circle is divided up into portions in which the area of each portion represents the size of the data.

**Pie Graph** - a diagram showing a system of connections or interrelations between two or more things by using a circle divided into segments that look like triangular pieces of a round pie.

**Place Value** - within a number, each digit is given a place value depending on it’s location within the number; ones, tens, hundreds, thousands.

**Plane** - a two-dimensional area in geometry.

**Plane Surface** - one with which a straight line joining any two of its points, will exactly coincide.

**Plus sign** - the + sign used to indicate the addition of numbers.

**Point** - has no dimension, it has position only.

**Point** - in geometry, a point represents a position, but has no size. A point called a vortex.

**Polar Axis** - a ray from the pole in a fixed direction, analogous to the x-axis in the Cartesian system. The angle between this fixed ray and a ray through the pole and the point of interest gives the value of theta in the coordinate pair (r,theta) used in the polar coordinate system.

**Pole** - in the polar coordinate system, a fixed point, analogous to the origin in the Cartesian coordinate system. The distance from this point to a point of interest gives the value of r in the coordinate pair (r,theta) used in the polar coordinate system.

**Polygon** - a closed plane figure formed by three or more line segments that do not cross over each other.

**Polyhedra** - any solid figure with an outer surface composed of polygon faces.

**Polyhedron** - a three-dimensional object whose faces are polygons.

**Polyomino** - a planar figure consisting of congruent squares joined edge-to-edge.

**Positive Number** - numbers that appear to the right of zero on the number line, a number having a plus sign either expressed or understood.

**Power** - either the number itself, or the product arising from using the number a certain number of times as a factor.

**Practical Number** - a positive integer m such that every natural number n not exceeding m is a sum of distinct divisors of m.

**Prime** - a number that has exactly two factors one and itself.

**Prime Number** - a number that has exactly two factors, 1 and the number itself.

**Primitive Pythagorean Triangle** - a right triangle whose sides are relatively prime integers.

**Primitive Root of Unity** - the complex number z is a primitive nth root of unity if zn=1 but zk is not equal to 1 for any positive integer k less than n.

**Principle** - a fundamental truth from which other truths are derived.

**Prism** - a polyhedron that is formed with two parallel polygons that are connected at the edges with rectangles.

**Prism** - a solid whose bases are equal polygons, and whose sides are parallelograms.

**Prisoners** - values for c in the Julia Set or Mandelbrot set where at each iteration the resulting value becomes smaller and smaller, approaching zero.

**Probability** - the measure of how likely it is for an event to occur.

**Problem** - a question to be solved.

**Product** - the answer when you multiply two (or more) numbers. Factor x Factor = Product.

**Pronic Number** - a number of the form n(n+1).

**Proof** - an argument that shows something (like a theorem) is true beyond any doubt.

**Proper Divisor** - the integer d is a proper divisor of the integer n if 0

**Proper Fraction** - a simple fraction whose value is less than one, the numerator is smaller than the denominator.

**Property of Zero for Multiplication** - zero times any number is zero.

**Proportion** - two ratios that are equivalent to each other, two equal ratios conected by an equal sign.

**Protractor** - an instrument used to measure and draw angles on a flat surface.

**Pyramid** - a three-dimensional solid whose base is a polygon and whose sides are triangles that come to a point at the top.

**Pythagorean Theorem** - the sum of the squares of the lengths of the legs of a right triangle is equal to the square of the length of the hypotenuse.

**Pythagorean Triangle** - a right triangle whose sides are integers.

**Pythagorean Triple** - an ordered set of three positive integers (a,b,c) such that a2+b2=c2.

**Pythagorean Triples** - whole numbers that work together in the Pythagorean theorem.

How to keep these definitions straight?

- Define the word.
- Make associations with related words.
- Draw or trace the image if possible.

Once children have a good definition explained to them and they then use the word in a sentence or Math word problem, they're much more likely to understand and remember the definitions.

I myself did not have an easy time remembering which was parallel and which was perpendicular until I began teaching Math. I remember them now because I've taught them and had to make the demonstrations, but also because the word parallel has the double L clue - those letters themselves are parallel. It's also a good way to remember that the spelling has the L twice.

I print and keep these Math definitions as a glossary in my binder: Free Printable Math Dictionary For Kids.

You can also download it to your tablet or bookmark the page.

See the alphabetical links below for more online Math words.

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