Answer:
144 cm squared
Explanation:
The steps are same as for the calculation of area of the octagon I solved for you earlier. That is why I will post here only calculations and not the actual steps.
360/10=36 degrees
36/2=18 degrees
sin(18)=x/7
x= 2.1631 cm
Cos(18)=y/7
y=6.6573
y*x= 14.4006
14.4006*10=144 cm squared