Xét ΔABC có:
\(\widehat{A}+\widehat{B}+\widehat{C}=180^0\\ \Rightarrow\widehat{x}=\widehat{C}=180^0-\widehat{B}-\widehat{A}\\ =180-75-66\\ =39\left(^0\right)\)
Xét ΔEDF có:
\(\widehat{F}+\widehat{E}+\widehat{D}=180^0\\ \Rightarrow\widehat{x}=\widehat{F}=180-\widehat{E}-\widehat{D}\\ =180-37-63\\ =80\left(^0\right)\)
Xét ΔHGI có:
\(\widehat{H}=\widehat{I}=x\)
⇒ΔHGI cân tại G
\(\widehat{H}+\widehat{I}+\widehat{G}=180^0\\ \Rightarrow\widehat{H}+\widehat{I}=180-\widehat{G}\\ \widehat{x}+\widehat{x}=180-136\\ 2\widehat{x}=44\\ \widehat{x}=44:2=22\left(^0\right)\)
Xét ΔJKL có:
\(\widehat{J}+\widehat{K}+\widehat{L}=180^0\\ \Rightarrow\widehat{L}=180-\widehat{K}-\widehat{J}\\ \widehat{x}=180-55-100\\ \widehat{x}=25\left(^0\right)\)
