Answer:
the first one
Step-by-step explanation:
the two planes intersect at line YZ, where they meet
tip: planes intersects at a line, just like how lines intersect at a point
hope this helps :)
If you are trying to find h, then its very simple.
So lets see 5+7=12
So 17-12=5
So lets check to see if h=5
5+5+7
5+5=10+7=17 so h is 5. :)
