Surface area
Surface area is total area of the surface of a three-dimensional object measured in square units.
https://en.wikipedia.org/wiki/File:Area_conversion_-_square_mm_in_a_square_cm.png
Metric Units – Area
1 square metre = 10 000 square centimetres, cm2
1 hectare = 10 000 square metres, m2
1 square kilometre = 100 hectares, ha
1 square metre = 100 square decimetre, dm2
1 square decimetre = 100 square centimetre, cm2
1 square centimetre = 100 square millimetre, mm2
Surface area formulas
Cube |
Square area = a2A = 6 square areaA = 6 a2 |
a – base lenght |
Rectangular prism |
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A = 2lw +2wh + 2lh= = 2(lw +wh+lh) |
l – lenght, w – width, h – height |
Triangular prism |
SA= LSA + 2 B LSA = aH + bH + cH = A = 2 (ah/2) + (a+b+c)H =ah+PH |
SA – surface areaB – triangular faces area, base area LSA – lateral surface areaa – length of one side of the triangle,h – length of an altitude drawn to side
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n-gonal prism |
SA= LSA + 2 BA =PH + 2B |
SA – surface areaB – base area LSA – lateral surface areaB – base area (regular polygon area)
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Square pyramid |
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SA= LSA + B A = B + 1/2 x P x l P = 4a LSA =1/2 x P x l= = 1/2 x 4a x l =2al B = a2 Lateral surface area of a pyramid (LSA) = Sum of areas of the lateral surfaces of the pyramid |
SA – surface areaLSA – lateral surface area B – bases area a -base´s side lenghtH – perpendicular height, height of the pyramidB – area of pyramid baseP – perimeter of the base l – slant length of the lateral sides (lenght base to vertex, apex) |
Triangular Pyramid |
SA= LSA + B SA = B + 1/2 x P x l LSA =1/2 x P x l Bases area = polygon area Lateral surface area of a pyramid (LSA) = Sum of areas of the lateral surfaces (triangles) of the pyramid |
SA – surface areaLSA – lateral surface area B – bases area P – base perimeter H – perpendicular height, height of the pyramida -base´s side lenghtl (m) – slant length of the lateral sides. Bases area = polygon area h – height of the triangle |
Sphere |
SA = 4πr2 |
r – radius |
Right circular cone |
Total Surface Area of Cone = Area of Curved Surface + Base Area |
B – area of the baseH, h – perpendicular height, height of the coner – radius |
Cilinder |
Area = 2 · the area of the base + base circumference · height |
B – base area
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