Nahh i need help i really dont know anything about history im just here for answers
Because Francis was assassinated by a serbian, Austria-Hungary declared war on Serbia, which triggered the domino effect of the central powers declaring war on everyone. Causing World War 1.
He caused ww1
tan A should be the corner try work out work out:

first and then add all the others (B=90)
Explanation:
A and C should be the same
Means memory or heritage from a certain past