Question

If sides BD and D.C. have the same length , what is the length of side BC

Answer 1

BD=DC=$\sqrt{1+1}$=$\sqrt{2}$
BC=$\sqrt{BD+DC}$=2

Answer 2

Answer:

Option 3rd is correct.

Step-by-step explanation:

Given: AB = AD = 1 unit   and BD = CD

We have to find, CB

In ΔABD,

using Pythagoras theorem

BD² = AB² + AD²

BD² = 1² + 1²

BD = ± √2

BD = √2   (length can not be negative)

CD = BD = √2

Again using Pythagoras theorem in ΔBDC

CB² = BD² + CD²

CB² = (√2)² + (√2)²

CB² = 2 + 2

CB² = 4

CB = 2

Therefore, Option 3rd is correct.