Question Number 189421 by normans last updated on 16/Mar/23
Commented by mr W last updated on 16/Mar/23
$${terrible}\:{diagram}:\: \\ $$$${not}\:{clear}\:{if}\:{circle}\:{tangents}\:{the}\:{semi} \\ $$$${circle}. \\ $$$${not}\:{clear}\:{which}\:{angle}\:{is}\:{meant}. \\ $$
Answered by mr W last updated on 16/Mar/23
$$\frac{\mathrm{7}}{\mathrm{7}+\mathrm{8}}×\mathrm{180}°=\mathrm{84}° \\ $$$$\mathrm{90}−\mathrm{84}=\mathrm{6}° \\ $$$$\frac{\mathrm{6}°}{\mathrm{2}}=\mathrm{3}° \\ $$$${x}=\mathrm{90}°−\mathrm{3}°=\mathrm{87}°\:\checkmark \\ $$