Question

Can you please help me ​

Answer 1

I think its 72

Explanation:

Im not 100% but i think you have to add every side and you have to comlite 180 so 180-78-30=72.....

Im sure that this is what you do with the corners but it could be the same for the sides maybe

Answer 2

Answer = 72

Use Pythagorean theorem

a² + b² = c²

30² + b² = 78²

b² = 5184

b = √5184

b = 72