Question

Can someone please help me?

Answer 1

$4x + 18 = 90$
Does this help?

Answer 2

Hi! The interior degrees of triangles will always equal 360. Since two out of the three are 45°, this automatically means the third equals 90°. To find this, we set up an equations to look like this.
$4x + 18= 90$
Now we'll subtract 18 from both sides.
$4x = 72$
Divide both sides by 4 to solve for x.
$x = 18$