In a right-angled triangle, one of the angles is 42 degrees. What is the other acute angle?

Let’s call the constructed right-angled triangle ABC.
Let the angle A be right.
That is, you can write.
A = 90 °.
As a rule, the sum of all the angles of a triangle is 180 °.
Therefore, we will write ABC for our triangle.
A + B + C = 180 °.
By condition, it is also given that one of the angles of this triangle is 42 °.
Let this be angle B.
B = 42 °.
Now we substitute the values of A and B into the expression A + B + C = 180 ° and find the value of the angle C.
90 ° + 42 ° + C = 180 °.
132 ° + C = 180 °.
C = 180 ° – 132 °.
C = 48 °.
Thus, the other acute angle is 48 °.
So, we choose the answer at number one.