How does multiplying a vector by a scalar value of -pi change the vector?
a) the vector will change direction and increase in magnitude.
b) the vector will change direction and decrease in magnitude.
c) the vector will not change direction but will increase in magnitude.
d) the vector will not change direction but will decrease in magnitude.

Step-by-step explanation:

Example:  <2, 3>

Mult. this vector by -pi results in:  -π<2, 3> or <-2π, -3π>

This will reverse the direction of the given vector and increase its magnitude ( Answer (a) )

check the picture below.

well, the angle at the vertex d is clearly not a right-angle, let's check for the one at the vertex f which does look like,   however if it's indeed, that means ef is perpendicular to df, in which case their slopes will be negative reciprocal of each other.

so the negative reciprocal of the slope of ef is 1, however the slope of df is not 1, is 1/2, so nope, they're not perpendicular lines.

19.side- angle- side

20. angle- side- angle

step-by-step explanation: