Step 1 :

Slope of the line joining the points (3, -4) and (-2, 6) is

$m_1 = \large\frac{y_2-y_1}{x_2-x_1}$$ = \large\frac{6-(-4)}{-2-3}$$ = \large\frac{10}{-5}$

$=-2$

Slope of the line joining (-3, 6) and (9, -18) is

$m_2 = \large\frac{-18-6}{9-(-3)}$$ = \large\frac{-24}{12}$$=-2$

If two lines are perpendicular, then the product of their slopes is -1.

( i.e ) $m_1m_2=-1$

But let $m_1m_2 = 4$

Hence the statement is falser.