Question Number 191324 by Mingma last updated on 23/Apr/23
Answered by HeferH last updated on 23/Apr/23
$$\mathrm{r}\:=\:\mathrm{20} \\ $$$$\mathrm{S}\:=\:\frac{\mathrm{15}×\mathrm{20}}{\mathrm{2}}\:+\:\frac{\mathrm{7}×\mathrm{24}}{\mathrm{2}}\:=\:\mathrm{150}+\mathrm{84}\:=\:\mathrm{234}\:\mathrm{u}^{\mathrm{2}} \: \\ $$
Commented by Mingma last updated on 23/Apr/23
Excellent!