Answer:
Yes
Explanation:
It is a right angle because it is 90 degrees.
Also,you can tell its a right angle because the variables a, b, and c
represent the Pythagorean Theorem which is used for finding missing lengths of a right triangle.
I didnt see the part at the bottom but the explanation for that would be
50+40> 30 True 40 squared + 30 squared= 50 squared
50+30> 40 True or 1600+900=2500
40+30> 50 True 2500=2500