How do you find area of an irregular shape with the help of a graph paper
Answers
- Assemble Your Tools
Collect the area formulas for shapes you're already familiar with. The most common shapes and their formulas include:
Area of a square or rectangle = l × w (where l is length and w is width)
Area of a triangle = 1/2(b × h) (where b is the triangle's base and h is its vertical height)
Area of a parallelogram = b × h (where b is the parallelogram's base and h is its vertical height)
Area of a circle = π_r_2 (where r is the radius of the circle)
- Subdivide the Irregular Shape
Use your imagination to subdivide the irregular shape you have into more familiar shapes.
- Find the Dimensions of the Subdivided Shapes
Refer back to your area formulas for the dimensions you'll need to calculate the area of each subdivided shape. In this case, you'll need the base and vertical height of the triangle and the length and width (or two adjacent sides) of the rectangle.
- Calculate the Area of Each Subdivided Shape
Fill the dimensions into the area formula for each subdivided shape. For example, if the triangle has a base of 6 inches and a vertical height of 3 inches, its area formula is:
1/2(b × h) = 1/2(6 in × 3 in) = 1/2(18 in2) = 9 in2
If the rectangle has a length of 6 inches (which is also the side that makes up the base of the triangle) and a height of 4 inches, its area formula is:
l × w = 6 in × 4 in = 24 in2