13. Five marks example problems VII

1. Calculate the distance between the points \(A(7, 3)\) and \(B\) which lies on the \(x\)-axis whose abscissa is \(11\).

 

Distance \(=\)  units

 

 

2. Find the value of '\(a\)' such that \(PQ = QR\) where \(P\), \(Q\) and \(R\) are the points whose coordinates are \((6, -1)\), \((1, 3)\) and \((a, 8)\) respectively.

 

$a=i$ or $a=i$

 

[Note: Enter the number from greatest to smallest]