Help me in this math problem I need to send it today​

James adds two numbers a + b. sally adds the same two numbers but reverse the order b + a what property of addition assures us that james and sally will get the same sum

Astick 2 m long is placed vertically at point b. the top of the stick is in line with the top of a tree as seen from point a, which is 3 m from the stick and 30 m from the tree. how tall is the tree?

The measure of an angle is 117°. what is the measure of a supplementary angle?