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 = a2
A circle's area is given by the formula Acircle=π*r2
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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