Area and Perimeter of Polygons
The perimeter of a polygon is equal to the sum of the length of its sides.
The area of a polygon is the measure of the region enclosed by the sides of a polygon.
Perimeter of a Triangle
|Equilateral Triangle||Isosceles Triangle||Scalene Triangle|
Area of a Triangle
Find the area and perimeter of the following triangle:
P = 2 · 11 + 7.5 = 29.5 cm
Calculate the area and perimeter of a square with 5 cm sides.
A = 52 = 25 cm2
Calculate the area and perimeter of a rectangular with a base of 10 cm and a height of 6 cm.
P = 2 · (10 + 6) = 32 cm
A = 10 · 6 = 60 cm2
Calculate the area and perimeter of a rhombus whose diagonals are 30 and 16 cm, and its side measures 17 cm.
P = 4 · 17 = 68 cm
P = 2 · (a + b)
A = b · h
Calculate the area and perimeter of a rhomboid shape of 4 sides of 4.5 cm and a height of 4 cm.
P = 2 · (4.5 + 4) = 17 cm
A = 4 · 4 = 16 cm2
Area of a Trapezoid
Calculate the area of the following trapezoid:
Area of a Regular Polygon
n is the number of sides
Calculate the area and perimeter of a regular pentagon with sides of 6 cm.
By applying the Pythagorean theorem for one of the triangles, we obtain:
Calculate the area and perimeter of a regular hexagon inscribed in a circle of 4 cm radius.
P = 6 · 4 = 24 cm
Area of a Polygon
The area is obtained by triangulating the polygon and adding the area of these triangles.
A = T1 + T2 + T3 + T4
Calculate the area of the following polygon:
P = 11 · 2 + 5 + 13 + 12 = 52 cm
AD = BC; AB = DC Rhomboid
A = AR + AT
A = 11 · 12 + (12 · 5 ) : 2 = 162 cm2