5.18 is irrational because it cannot be a fraction.
The answer is 6 cm. The mid segment is half of BC
Answer:
B
Step-by-step explanation:
A rhombus is divided into four congruent triangles. The two given angles are complementary, meaning they add up to 90 degrees. Set up an equation:

Take out the parentheses
Combine like terms
Add 25 to both sides so as to isolate the variable
Divide both sides by 5
Answer:
x = 9
Step-by-step explanation: