Answer:
x = 7
Step-by-step explanation:
Since this is a right triangle, we can use a trig function
tan theta = opposite/ adjacent
tan 45 = 7/x
Multiply each side by x
x tan 45 = 7
Divide each side by tan 45
x = 7/ tan 45
7
It is a 45 45 90 triangle
meaning that the side lenghts will be x, x, x root 2
the hypotenuse will be x root 2, so that means that the side length will be 7
