Not sure how to find what x equals

Its 48 °

Since its a triangle, the total angle will be 180°

So,

x° + 42°+90°=180°(90° as one angle in triangle is 90°)

x°=180°-90°-42°

x°=48°

48º c:

Step-by-step explanation:  So basically the angle at the top, lets call it A, is 42º. And the angle at the bottom right, is a right angle, which is 90º. We know this by the square at the angle. If we call this angle B, then through the fact that triangles will always have a combined angle measuremnt of 180º, we can do a + b + x = 180, which will be 42 + 90 = 132, 180 - 132 = 48 :)

is this like a trig problem