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Basic Geometry

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How to Recognize a Polyhedron

A polyhedron is the three-dimensional equivalent of a polygon, which is a shape that has only straight sides. Similarly, a polyhedron is a solid that has only straight edges and flat faces [more…]

How to Measure in Three Dimensions

Measuring in three dimensions is similar to measuring in two dimensions; however, in 3-D, the boundary of a solid is called its surface area (not its perimeter) [more…]

Compare Numbers Using a Bar Graph

A bar graph gives you an easy way to compare numbers or values. For example, the following figure shows a bar graph comparing the performance of five trainers at a fitness center. [more…]

Use a Pie Chart to Find Percentages and Amounts

A pie chart, which looks like a divided circle, shows you how a whole object is cut up into parts. Pie charts are most often used to represent percentages. For example, the following figure is a pie chart [more…]

Plot Numbers Using a Line Graph

The most common use of a line graph is to plot how numbers change over time. For example, the following figure is a line graph showing last year’s sales figures for Tami’s Interiors. [more…]

Common Area and Perimeter Formulas

You may need to find out the size of an office space, perimeters of buildings, and tracts of land for your business. Keep these frequently used formulas handy for your business math needs: [more…]

Important Angle Measures in Degrees

When you’re figuring out things like lot lines or fencing for your business, you’re working with angles. These figures are the more commonly used angle measures and can help you estimate angles for your [more…]

Formulas for Perimeter, Area, Surface Area, and Volume

You'll find geometric figures showing up frequently in word problems. Geometric figures have names, classifications, and characteristics and are measured in two or more ways. Study this list of the formulas [more…]

Plane Geometry: Points, Lines, Angles, and Shapes

Plane geometry is the study of figures on a two-dimensional surface — that is, on a plane. You can think of the plane as a piece of paper with no thickness at all. Technically, a plane doesn't end at the [more…]

Common Polygons

A polygon is any shape whose sides are all straight. Every polygon has three or more sides (if it had fewer than three, it wouldn't really be a shape at all). Following are a few of the most common polygons [more…]

How to Measure Four-Sided Shapes

Two important skills in geometry — and real life — are finding the perimeter and calculating the area of shapes. A shape's perimeter is a measurement of the length of its sides. You use perimeter for measuring [more…]

How to Measure Triangles

You can measure the perimeter and area of all triangles. There also is a special feature of right triangles that allows you to measure them more easily. [more…]

How to Measure Circles

The center of a circle is a point that's the same distance from any point on the circle itself. This distance is called the radius of the circle, or r for short. And any line segment from one point on [more…]

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