Math, asked by AdhyayanDubey3245, 9 months ago

The perimeter of regular octagon with length of the side as 5cm is

Answers

Answered by Anonymous
5

the perimeter is 40

since octagon has 8 sides,and a regular one...

8×5=40

hope it helps...

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Answered by Anonymous
1

QUESTION:-

The perimeter of regular octagon with length of the side as 5cm is

Answer:

Step-by-step explanation:

Let ABCDEFGH. is a regular octagon whose. center is O. In isosceles ∆

OAB. OA=OB , AB= 5 cm. and angle AOB = 45°. draw OP perpendicular

on AB

In right triangle APO :-

AP=AB/2=5/2=2.5. cm. and angle AOP=45/2=22.5°

AP/OP=tan 22.5°

2.5/OP = 0.4142

OP =2.5/0.4142 = 6.0357 cms.

Area of triangle OAB = ( AB ×OP)/2 = ( 5 ×6.0357)/2

Area of regular octagon ABCDEFGH =8×area of ∆ OAB.

=8×(5×6.0357)/2

=20×6.0357

= 120.714O sq. cm

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