i dont understand this

Answer:
a²+b²=c²
14²+10²=c²
196+100=c²
296=c²
√296=√c²
√296=c
I hope this helps:
Answer:
I believe the missing length is 70
Step-by-step explanation:
Multiply 14 × 10 = 140
Since its a triangle, divide in half because 140 is the area if it were a rectangle and triangle is half of a rectangle.
140 ÷ 2 OR 140 × 1/2 both = 70
Sorry if it's wrong, please lmk if it is!!