Answer:
[tex]y=7\sqrt{2}[/tex]
Step-by-step explanation:
Notice that the problem is about a right triangle, where the opposite leg is 7 and the acute angle is 45°.
This is an special right triangle because it has acute angles of 45°, that means the legs are congruent, because it's a symmetric right triangle. Basically, when a right triangle has acute angles of 45°, it means is an isosceles triangle too.
Additionally, a special right triangle like this has a pattern, its hypothenuse is [tex]x\sqrt{2}[/tex], where [tex]x[/tex] is the length of a leg.
So, in this case, the hypothenuse is
[tex]y=7\sqrt{2}[/tex]
And the missing leg is [tex]x=7[/tex].
