If two of a triangles angles measure 42 degrees and 48 degrees, how would you classify that triangle

That depends on the last angle. if the last one is less than 90 degrees, it would be an acute triangle. if the last angle is greater, it would be obtuse.if the last angle is exactly 90, it would be a right.

First add 42 + 48 to get 90 degrees. In a triangle, the total 3 angles add up to 180. So, reduce
180 - 90= 90
The triangle is a right angled triangle.

180 - (42 +48)
180 - 90
=90 : third angle