Geometry Practice Test 5

We know that according to the given figure,
PA. PB = PC. PD
x × (x + 6) = (5) (8)
${\mathit{x}}^2$ + 6x = 40
${\mathit{x}}^2$ + 6x − 40 = 0
${\mathit{x}}^2$ +10x − 4x − 40 = 0

${\mathit{x}}^2$ +10x − 4(x +10) = 0
(x +10) (x − 4) = 0
x = 4 cm
PA = 4 cm