Answer:
72
Step-by-step explanation:
The pythagorean theorem states that in a right triangle A^2 + B^2 = C^2 where A and B are the two smaller sides and C is the hypotenuse.
Because of this, in this triangle 30^2 + B^2 = 78^2
Which means B^2 = 5184
And B = 72
last one because you can solve it to many way6s
288
360/5 = 72
72x4 = 288
X can be - 1/2 or 0.5
2x0.5=-1
