What is the area of this composite shape

You might have noticed various shapes and figures around you. Everything has an area they occupy, from the laptop to your book. There are various shapes whose areas are different from one another. These shapes are known as composite figures. A composite figure is made up of simple geometric shapes. It is a 2-dimensional figure of basic two-dimensional shapes such as squares, triangles, rectangles, circles, etc.

To understand the dynamics of composite figures, one needs first to cover the basics of real two-dimensional geometric figures. Because at the end of the day, composite figures are the sum of basic figures.

Basic Properties of Two-Dimensional figures:

2 D Shapes Properties 
Triangle It can have no, 2 or 3 equal sides It can have no, 2 or 3 equal angles It can have up to 2 axes of symmetry
Square Four equal sides Four equal angles(90°) Four axes of symmetry
Rectangle 2 sets of 2 equal sides Four equal angles(90°) Two axes of symmetry
Circle Constant diameter and radius The total angle of a circle is equal to 360 degrees Almost infinite axes of symmetry going through the center
Triangle It can have no, 2 or 3 equal sides It can have no, 2 or 3 equal angles It can have up to 2 axes of symmetry
pentagon 5 sides (can be equal or unequal) 5 angles (can be equal or unequal) It can have up to 5 axes of symmetry
hexagon 6 sides (can be equal or unequal) 6 angles (can be equal or unequal) It can have up to 6 axes of symmetry
Octagon 8 sides (can be equal or unequal)  8 angles (can be equal or unequal) It can have up to 8 axes of symmetry
Parallelogram 2 sets of 2 equal sides 2 sets of 2 equal angles Usually no axes of symmetry
Rhombus All sides are the same length 2 sets of 2 equal angles 2 lines of symmetry
Trapezium At least 2 parallel sides Can have pairs of equal angles It can have a line of symmetry

Area of Composite Figures

The area of composite figures is the area that any composite shape covers. A composite shape comprises a few polygons that are joined together to form the desired shape. These shapes or figures can be made up of triangles, squares, and quadrilaterals, among other things. To calculate the area of a composite shape, divide it into basic shapes such as squares, triangles, rectangles, hexagons, etc.

A composite shape is made up of basic shapes that have been combined. It is also referred to as a “composite” or “complex” shape.

Now that we have figured out the basic properties of the important polygons, we can move into understanding the area and perimeter of the polygons:

2d Shape Area Perimeter
Circle Πr2 (R is the radius of the circle) 2πr
Triangle ½ (Base x height) Sum of three sides
Square Side2 4(Side)
Rectangle Length x Breadth 2(Length + Breadth)
Rhombus ½ (Product of diagonals) 4(Side)
Parallelogram Base x Height 2 (Base + Side)

The volume of Composite Figures

Understanding volume when it comes to finding areas is crucial. You must know the volumes to calculate areas of various sections when limited data is provided. In mathematical terms, volume is the amount of space inside a 3-D object. First, we will understand some basic terms needed to find the volume of composite figures. Then we will get into the formulae.

Solid Figure: Three-dimensional figures of simple geometric shapes are called solid figures. Some examples of solid figures are cubes, prisms, pyramids, and cylinders. The volume of a Solid figure: The volume of a solid figure is the measure of the enclosed space within the figure.

Composite Figure: Figures constructed by connecting different solid figures are composite figures. The volume of a Composite Figure: Sum of the volumes of the given solid figures.

Let us understand the properties of some basic 3D objects like the way we discussed for the 2D objects:

3D Shapes Properties
Sphere (With radius – r) It has no edges or vertices (corners). It has one curved surface. It is perfectly symmetrical. All points on the surface of a sphere are at the same distance (r) from the center.
Cone It has a flat base. It has one curved side and a one-pointed vertex at the top or bottom known as the apex.
Cylinder It has a flat base and a flat top. The bases are always congruent and parallel. It has one curved side.
Cube It has six faces in the shape of a square. The sides are of equal lengths.12 diagonals can be drawn on a cube.
Pyramid A Pyramid is a polyhedron with a polygon base and an apex with straight lines. Based on their apex alignment with the center of the base, they can be classified into regular and oblique pyramids.
Prism It has identical ends (polygonal) and flat faces. It has the same cross-section all along its length
Cuboid It has six rectangular faces. All the sides of a cuboid are not equal in length.12 diagonals can be drawn on a cuboid.

How to Find Volume of a Composite Figure?

  • Measure the dimensions of the bottom solid figure and find the volume.
  • Measure the dimensions of the top solid figure and find the volume.
  • Find the volume of the composite figure by adding the volume of the two solid figures.

Some of the important formulae regarding finding the surface areas and volumes of various composite figures:

3D Shape Formulas
Cone Curved Surface Area = πrl; (where ‘l’ is the slant height and
l = √(h2 + r2))
Total Surface Area = πr(l + r)
Volume = (1/3)πr2h
Cylinder Total Surface Area = 2πr(h+r); (where ‘r’ is the radius and ‘h’ is the height of the cylinder)
Volume = πr2h
Sphere Diameter = 2 × r; (where ‘r’ is the radius)
Surface Area = 4πr2
Volume = (4/3)πr3
Cube Lateral Surface Area = 4a2; (where ‘a’ is the side length of the cube)
Total Surface Area = 6a2
Volume = a3
Cuboid Lateral Surface Area = 2h(l + w); (where ‘h’ is the height, ‘l’ is the length and ‘w’ is the width)
Total Surface Area = 2 (lw + wh + lh)
Volume = (l × w × h)
Pyramid Surface Area = Base Area + (1/2 × Perimeter × Slant Height)
Volume = [(1/3) × Base Area × Altitude]
Prism Surface Area = [(2 × Base Area) + (Perimeter × Height)]
Volume = (Base Area × Height)

How to find the area of a Composite Figure?

Finding the areas of composite figures is not much challenging. You have to memorize the formulae by heart and do the calculations. You can score more if you learn the formulae and practice them regularly. The area of the composite figures is the area of one or more simple polygons and circles combined. We can add the areas of all the basic figures together to calculate the area of the composite figures. Find the area of each shape and add them together to find the area of the composite figure. For example, the area of composite shapes is measured in m2, cm2, in2, or ft2.

Example:

  1. Find the area of the composite figure when – 1. There is a rectangle of 4cm and 3cm in height & length, respectively. 2. A triangle with a 5cm base, 10cm height

      A: As we have learned in the past, a composite figure is a summation of basic polygons. So to find the area of composite figures, we have to break the figure into small polygons and then apply the formula as required.

Hence the area of the rectangular- 4 x 3 = 12 square cm

Area of the triangle – ½ x 10 x 5 = 25 square cm

Therefore, the total area of the composite figure = 12 + 25 = 37 square cm 

  1. A composite figure has an area of 100 units square. The shape is composed of a circle and a triangle, and the area of the triangle is 64 units square. What is the area of the circle?

      A: Given the area of the composite figure = 100 units square and the area of the triangle = 64 units square

Using the formula for the area of the composite shape, Area of composite shape = area of triangle + area of the circle.

⇒ 100 = 64 + area of circle

⇒ Area of circle = 100 – 64

⇒ Area of the circle = 36 units square.

Therefore the area of the circle is 36 units square.

Frequently Asked Questions

1. What is a composite figure?

Ans. A composite figure is a drawing that represents multiple objects. Composite figures are often found in art, where they can be used to create the illusion of depth.

2. What is composite figure formula?

Ans. Composite figure formula is a formula to find the area of a composite figure. The formula is:

Area = (Area of rectangle) + (Area of triangle)

The rectangle is the area between the x-axis and y-axis, while the triangle is the area between the x-axis and line y=k.

3. What is a composite figure or shape?

Ans. A composite figure is a shape that is made up of two or more other shapes.It can be difficult to determine which shapes combine to make one composite shape, and this can be a problem for people with dyslexia.

4. How do you find the value of composite figures?

Ans. You can find the value of composite figures by adding together the values of their component parts. For example, if you have a composite figure made up of two triangles and one square, you add up the values of each triangle and then add them to the value of the square.

5. How do you find the length of a composite figure?

Ans. The length of a composite figure is the sum of all of its component parts. The formula for finding the length of a composite figure is length = ∑(length of each component)

How do you find area of a composite shape?

A composite figure is made up of simple geometric shapes. To find the area of a composite figure or other irregular-shaped figure, divide it into simple, nonoverlapping figures. Find the area of each simpler figure, and then add the areas together to find the total area of the composite figure.

What is the composite shape?

A composite shape can be defines as a shape created with two or more basic shapes. We often refer to composite shapes as compound and complex shapes as well. We see composite shapes every day. The shape of your curved bookcase, the mouse you are scrolling, and the bag you are carrying are all composite shapes.