Question

find area of octagon​

Answer 1

Answer:

Area of octagon=156cm²

Step-by-step explanation:

In ΔABH,

(AB)²=(AH)²+(HB)²

(5)²=(3)²+(HB)²

25=9+(HB)²

(HB)²=25-9

(HB)²=16

HB=√16

HB=4cm

Therefore, the area of octagon

=2×(Area of ΔABH)+Area of rectangle BCFG

=2×½×b×h+l×b

=b×h+l×b

=3×4+9×16

=12+144

=156cm²