Answer:
19.365
Step-by-step explanation:
The Pythagoreum Theorum tells us that:
a² + b² = c²
where a and b are the legs and c is the hypotenuse.
BC is a leg; we'll lable it a.
AC is the hypotenuse thus labled c.
Plugging their lengths into the above formula will solve for the missing leg length.
5² + x² = 20²
25 + x² = 400
x² = 375
✓x = ✓3 x (5 x 5) x 5
x = 5✓15
x = 19.365
