Answer:
![y=7√(2)](https://img.qammunity.org/2020/formulas/mathematics/middle-school/zpknm7molvv47c2ceb3sxco9tzimkv0u03.png)
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
, where
is the length of a leg.
So, in this case, the hypothenuse is
![y=7√(2)](https://img.qammunity.org/2020/formulas/mathematics/middle-school/zpknm7molvv47c2ceb3sxco9tzimkv0u03.png)
And the missing leg is
.