Question

please help me tomorrow is my exam ques no 4

Answer 1

Given: Octagon having eight equal sides, each 5 m. 

Construction: Divided the octagon in 3 figures, two trapeziums whose parallel and perpendicular sides are 11 m and 4 m respectively and third figure isrectangle having length and breadth 11 m and 5 m respectively.

now,
area of a trapezium= 2×1/2(a+b)×h
=2×1/2(11+5)×4
=64m^2
And , area of rectangle=l×b
11×5=55m^2

therefore total area of octagon=64+55=119m^2

HOPE IT WILL WORK FOR YOU.....

Answer 2

we can divide the figure into 2 rectangle of 4,5.. area is 20+20=40sq.m

middle rectangle area is 55sq.m

angle it have 4 triangles area=1/2*b*h
I. e, 12/2=6
6*4=24sq.m

all together the area of octagon is 40+55+24=119sq.m