Answer:
CD = 11
Step-by-step explanation:
From the figure we can see two right angled triangle.
AB ║ CD therefore <BCD = <ACD
<ABC = <DAC = 90°
To find the value of BC
BC²= AC² - AB
= 6² - 5² = 36 - 25
= 11
BC = √11
To find the value of CD
ΔABC and ΔADC are similar triangles.
The ratio of of corresponding sides of similar triangles are equal.
BC/AC = AC/CD
√11/6 = 6/CD
CD =(6 * 6)/√11
= 36/3.32 = 10.84 ≈ 11
