Answer:
50 degrees
Explanation:
all inside angles in every triangle can be added up to equal 180 degrees.
this is a right angle, so one has to be 90 degrees
on the bottom right it's marked 140 degrees on the outside, in order to find the inside angle, you need to subtract 140 from 180, which gives you 40 degrees
180-90=90
90-40=50
so the answer is 50
if that's not clear enough leave a comment, hope this helps!