Lol I just needed help with this kinda stuff...
I’m not very caught up with this stuff I feel your pain I’m very sorry if I’m wrong =/
10?
Just do a line crossing another in a angle of 90°
1 is linear pair with 2, 2 is linear pair with 3, 3 is linear pair with 4 and 4 is linear pair with 1.
<span>D. r + (-r) = 0
</span>
The additive inverse<span> of a number a is the number that, when added to a, yields zero. This number is also known as the opposite.</span>