rectangle

Home » rectangle

What is a trapezoid? Simple geometry

By |2017-07-29T13:16:13+00:00July 29th, 2017|Math|

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 sides, and a rhombus is a special kind of parallelogram, and so are rectangles and squares. To figure out the perimeter of a trapezoid, you can add the lengths of [...]

What is a square? Simple geometry

By |2018-04-23T16:01:49+00:00July 29th, 2017|Math|

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 has four sides all of equal length, and four corners, all right angles (90 degree angles). So a square is a kind of rectangle. To figure [...]

What is a rhombus? Simple geometry

By |2018-04-23T16:01:48+00:00July 29th, 2017|Math|

This is a rhombus, divided so you can figure out the area. A rhombus is a kind of quadrilateral that has two sides that are parallel to each other, and another two sides that are parallel to each other. A rhombus is a special kind of parallelogram, and squares and rectangles are special kinds of rhombus. To figure out the perimeter of the rhombus, you [...]

Rectangle – area and perimeter

By |2018-04-23T16:01:22+00:00July 29th, 2017|Math|

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, and two other sides of equal length opposite each other, and four corners, all right angles (90 degree angles). A square is a special kind of rectangle. [...]

What is a quadrilateral? Squares and rectangles

By |2017-07-29T12:01:49+00:00July 29th, 2017|Math|

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. And it has four corners. They can be at any angle  to each other so long as they add up to 360 degrees. A rectangle is [...]

Proof for the area of a circle

By |2018-03-14T12:32:23+00:00July 28th, 2017|Math|

Divide a circle up into sections like an orange We know it's true that A=πr-squared is the area of a circle, but how can we prove that it is always true for every possible circle? Here's how Euclid did it. Start by dividing a circle into sixteen sections like an orange. We know that together they add up to the [...]