Which two pairs of points lie on perpendicular lines?
a. (-6,-,18)
b. (6,,12)
c. (-4,,3)

(-6,-8),(7,18) and (-4,6),(2,3) lie on perpendicular lines

Step-by-step explanation:

we know that

The formula to calculate the slope between two points is equal to

step 1

Find the slope of the pair (-6,-8),(7,18)

substitute

step 2

Find the slope of the pair (6,4),(4,12)

substitute

step 3

Find the slope of the pair (-4,6),(2,3)

substitute

step 4

Remember that

If two lines are perpendicular, then their slopes are opposite reciprocal (the product of their slopes is equal to -1)

In this problem

and are opposite reciprocal

therefore

(-6,-8),(7,18) and (-4,6),(2,3) lie on perpendicular lines

c.   x=2.4cm

step-by-step explanation:

similar triangles are triangles which have the same shape but not the same size. this means their angle measures are equal but their side lengths are not instead they are proportional. to solve, we will set up a proportion and solve.

a proportion is two equal ratios set equal to each other. we form the ratios by finding corresponding sides (sides which match to each other on both triangles by their position). out ratios will be one side of the small triangle over the corresponding side on the big triangle as shown below:

.

to solve the proportion, we'll cross multiply by multiplying numerator with denominator across the equal sign.

-3.5 degrees per hour

step-by-step explanation:

find the unit rate:

-12   1/4 degrees           12.25 degrees

= - = -3.5 degrees per hour

      3   1/2 hours               3.5 hours