Answer:
22.4 cm
Step-by-step explanation:
You can use the Pythagorean Theorem to find the answer. You can form a triangle using sides AB, BE, and AE. The length of AB is 20 cm. The length of BE is 10 cm since it is half of a side. Plug these values into the Pythagorean Theorem and solve for c.
a² + b² = c²
(20)² + (10)² = c²
400 + 100 = c²
500 = c²
√500 = c
c = 22.4 cm
