Which half-circle is the largest on parallels or meridians?​

What is the approximate circumference of the circle shown below? 12.2 cm

Religious conflict in northern ireland started with a) cultural differences resulting from viking invasions around 800 b) england’s split from the catholic church in the 1500s c) rebellions in ireland between 1916 and 1921 d) the norman invasion of england in 1066

Which event had the greatest impact on culture of south america