Question Number 149510 by Tawa11 last updated on 05/Aug/21

Commented byAr Brandon last updated on 06/Aug/21

36−4×(9/2)=18cm^3

Commented byTawa11 last updated on 06/Aug/21

cm^2 ? And sir, how did you get 4 × 5

Commented byAr Brandon last updated on 06/Aug/21

Just some guess work, hahaha ! Maybe Mr W has a better method.

Commented byTawa11 last updated on 06/Aug/21

Hahahaha ... Thanks sir. I appreciate.

Commented byMJS_new last updated on 06/Aug/21

counting the white areas (1) left upper corner 2×2=4 (2) middle square + right lower corner 2×2=4 (3) the symmetric small ♮trianglesε 2×(2×2−2^2 π/4)=8−2π (4) the symmetric big ♮trianglesε 2×(4×4−4^2 π/4)=32−8π sum of these =48−10π = white area 36−(48−10π)=10π−12 = blue area

Commented byTawa11 last updated on 06/Aug/21

Thanks sir. God bless you.

Commented byTawa11 last updated on 07/Aug/21

Sir Mjs and ajfour. Thanks, I understand your solutions very well now. God bless you.

Answered by ajfour last updated on 06/Aug/21

B=(π/2)(4cm)^2 −2{4cm^2 −(π/4)(2cm)^2 } −4cm^2 =(10π−12)cm^2

Commented byTawa11 last updated on 06/Aug/21

Thanks sir. God bless you.