top surface of a raised platform is in the shape of a regular octagon as shown in the figure 14.12 find the area enclosed by octagonal figure
plz help
Answers
Answer:
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Step-by-step explanation:
AREA enclosed by the OCTAGON
= AREA OF ABCH + DEFG + CDGH
= [1/2(5+11)4] + [1/2(5+11)4] + (5x11)
= 32 + 32 + 55
= 119m²
AREA OF TRAPEZIUM
= 1/2(sum of parallel sides)
Answer:
The area enclosed by octagonal figure is 119 sq.M
Step-by-step explanation:
Given : Regular octagon side = 5 m
Solution :
Area of regular octagon ABCDEFGH = Area of Trapezium ABCH
+ Area of Trapezium GDFE
+ Area of Rectangle HFDC
Area of Trapezium ABCH = 1/2 x Height x ( Sum of parallel sides)
= 1/2 x AX x( AB + CH)
= 1/2 x 4 x (5+11)
= 1/2 x 4 x 16
= 32 sq.M
Area of Trapezium GDFE = 1/2 x Height x ( Sum of parallel sides)
= 1/2 x YF x ( GD + EF)
= 1/2 x 4 x ( 11 + 5 )
= 1/2 x 4 x 16
= 32 sq.M
Are of rectangle HGDC = Length x Breadth
= HC x CD
= 11 x 5
= 55 sq. M
Area of regular octagon ABCDEFGH = 32 + 32 + 55
= 119 sq. M