In today's lesson, we will use the strategy of calculating the area of a large shape and the area of the smaller shapes it encloses to find the area of the shaded region between them. Sometimes we … [Read more...] about Find the Area of the Shaded Region

# Area of Geometric Shapes

The area of a geometric shape is a property that describes how much space it takes up.

Regular geometric shapes like circles, parallelograms and triangles have simple formulas that give their area.

The area of irregular shapes can sometimes be computed by reducing it into several regular shapes.

Some common area formulas:

For triangles: Area = (h x b) /2

For rectangles: Area = h x w

Since a square is a special type of rectangle, its area is given by the same formula. But since in the square's case the width is the same as the hight, this becomes Area = a x a = a^{2}

A circle's area is given by the formula A_{circle}=π*r^{2}

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*Now that we've explained the basic concept of area in geometry, let's scroll down to work on specific geometry problems relating to this topic.*

## Find the Area of a Circle from 3 Points

Three points in a plane that are not all on the same line (not collinear) define a triangle, and any triangle can be circumscribed by a circle. So three points in a plane also define a circle. In this … [Read more...] about Find the Area of a Circle from 3 Points

## Equilateral Triangle: Find its Area from the Radius of an Inscribed Circle

This problem is the opposite of the one where we found the area of the inscribed circle using the length of the side of the equilateral triangle. Here we will use the circle's radius to find the area … [Read more...] about Equilateral Triangle: Find its Area from the Radius of an Inscribed Circle

## Area of an Irregular Shape

In today's lesson, we will find the area of an irregular shape by partitioning it into triangles. We've derived the basic formulas for the areas of regular shapes like triangles, rectangles, … [Read more...] about Area of an Irregular Shape

## Area of a Rhombus with a 60° angle

If we know the length of a side of a rhombus with a 60° angle, we can find its area in a number of different ways. We will use different properties of parallelograms, diamonds or equilateral … [Read more...] about Area of a Rhombus with a 60° angle

## Area of Similar Triangles

How do we find the area of similar triangles? The area of a triangle is given by the formula (base x height)/2. If we have similar triangles, their sides are proportional with a ratio given by a … [Read more...] about Area of Similar Triangles

## Area of a Parallelogram

In this geometry lesson, we'll derive the formula for the area of a parallelogram in two ways. First, we will use what we have already done when we found the area of a trapezoid - because we can … [Read more...] about Area of a Parallelogram

## Area of a Trapezoid

It is often possible to find the area of polygons with irregular shapes by dividing them into smaller shapes with easily computed areas, like triangles and rectangles. Sometimes this leads to a simple … [Read more...] about Area of a Trapezoid

## How to Find the Area of a Circle

The formula for the area of a circle is Acircle=π*r2 "π" is a special number, which is the same for all circles, and is the ratio between a circle's diameter and its circumference. The formula … [Read more...] about How to Find the Area of a Circle

## Circles: Finding the Area of a Ring

In today's lesson, we will learn how to find the area of a ring. A ring is a geometric shape made up of two circles with the same center point. We call such circles "concentric". Another name for a … [Read more...] about Circles: Finding the Area of a Ring