# right angle

29 07, 2017

## Sine waves – trigonometry – math

By |2017-07-29T17:59:39-07:00July 29th, 2017|Math|Comments Off on Sine waves – trigonometry – math

Sine wave In order to save energy, many, many things in nature move in a kind of repeated pattern we call a sine wave: water waves, sound waves, light waves, [...]

29 07, 2017

## Cosine – Trigonometry – Math

By |2019-04-26T10:01:02-07:00July 29th, 2017|Math|Comments Off on Cosine – Trigonometry – Math

Right triangle and cosine What is a cosine? A cosine, like a sine, is a mathematical way of thinking about a kind of movement that happens in nature. A cosine is [...]

29 07, 2017

## What is a triangle? Simple geometry

By |2017-07-29T13:19:10-07:00July 29th, 2017|Math|Comments Off on What is a triangle? Simple geometry

This is an equilateral triangle. A triangle is any set of three points on a plane and the lines connecting those points to each other, as long as the three points aren't all on the [...]

29 07, 2017

## What is a trapezoid? Simple geometry

By |2017-07-29T13:16:13-07:00July 29th, 2017|Math|Comments Off on What is a trapezoid? Simple geometry

This is a trapezoid. A trapezoid is a kind of quadrilateral that has at least two sides that are parallel to each other. A parallelogram is a trapezoid that has two pairs of parallel [...]

29 07, 2017

## What is a square? Simple geometry

By |2018-04-23T16:01:49-07:00July 29th, 2017|Math|Comments Off on What is a square? Simple geometry

This is a square. The darker purple line is the perimeter of the square. A square is a flat shape, in one plane, defined by four points at the four corners. A square [...]

29 07, 2017

## Right triangle – Simple geometry

By |2017-07-29T13:00:51-07:00July 29th, 2017|Math|Comments Off on Right triangle – Simple geometry

This is a right triangle, because one of the angles is a right angle. A right triangle is any triangle where one of the angles is exactly 90 degrees, or a right angle. You [...]

29 07, 2017

## Rectangle – area and perimeter

By |2018-04-23T16:01:22-07:00July 29th, 2017|Math|Comments Off on Rectangle – area and perimeter

This is a rectangle. A rectangle is a flat shape, in one plane. It's defined by four points at the four corners. A rectangle has two sides of equal length opposite each other, [...]

29 07, 2017

## What is a quadrilateral? Squares and rectangles

By |2017-07-29T12:01:49-07:00July 29th, 2017|Math|Comments Off on What is a quadrilateral? Squares and rectangles

This is a quadrilateral. A quadrilateral is a flat shape, in one plane, defined by four points at the four corners. A quadrilateral has four sides. The sides can be of any length. [...]

29 07, 2017