Question

Please I need the answer know
​

Answer 1

Answer:

Step-by-step explanation:

In a square all sides are equal :

AB=BC=CD=AD

LET THE SIDE OF THE SQUARE BE 'a'

diagonal of a square = a√2

AC is a diagonal :

so,

squaring AC

AC²=(a√2)²

=>AC²=2a²

[∵ a =side]

=>a=AB²

=>AC²=2AB²

hence proved.....

for more problem ask...

i am here to help.....

Answer 2

In a square all sides are equal.

Square ABCD has

AB = BC , BC = CD , CD = DA and DA = AB.

Since all angles in a square are 90°. Therefore angle ADC = 90°

${ac}^{2} = {ad}^{2} + {cd}^{2}$

we above prove that AD = AB so we can put AB in place of AD.

${ac}^{2} = {ab}^{2} + {cd}^{2}$

and above we also prove that CD = DA and DA = AB. so we can put AB in place of CD.

${ac}^{2} = {ab}^{2} + {ab}^{2}$

${ac}^{2} = 2 {ab}^{2}$

hence proved.