In the Fig.5.5, we have X and Y are the mid-points of AC and BC and AX = CY. Show that AC = BC.
Given, X is the mid-point of AC
AX = CX=
⇒ 2AX =2CX = AC …(i)
Y is the mid-point of BC.
BY = CY =
⇒ 2BY = 2CY= BC …(ii)
Also, given AX=CY …(iii)
According to Euclid’s axiom, things which are double of the same things are equal to one another.
From Eq. (iii),
2AX = 2CY
⇒ AC=BC [from Eqs. (i) and (ii)]