Answer: m∠CAD = 81°
Step-by-step explanation: <u>Diagonal</u> is a line that unites opposite sides.
ABCD is a prallelogram. One property of diagonal in a parallelogram is it separates the parallelogram in 2 congruent triangles.
The figure below shows ABCD with its diagonals.
Since diagonal divides a parallelogram in 2 congruent triangles, it means the internal angles are also congruent. So
m∠BAC = m∠CAD
4x + 5 = 5x - 14
x = 19
Then, m∠CAD is
m∠CAD = 5(19) - 14
m∠CAD = 81
The angle m∠CAD is 81°.
An arc of a circle has the same measure as the central angle that intercepts it.
Central angle 1 intercepts arc AB.
The measure of central angle 1 is the same as the measure of angle AB.
The measure of arc AB is 30 deg.
It’s rather half of that or double of that
The given equation is: 
To find the line perpendicular to it, we interchange coefficients and switch the signs of one coefficient.
The equation to a line perpendicular to it is:
$ 2y-x=c$
where, $c$ is some constant we have determine using the condition given.
It passes through $(2,-1)$
Put the point in our equation:
$2(-1)-(2)=c$
$c=-2-2$
$c=-4$
The final equation is:
$\boxed{ 2y-x=-4}$