Imagine two lines intersect. How can the properties of linear pairs and vertical angles help to determine the
angle measures created by the intersecting lines?
Explain.

Vertical angles are opposite angles that share only a vertex.

When two lines intersect, we have two sets of vertical angles.

Linear pairs are two angles that form a straight line; when two lines intersect, we have two linear pairs.  

If we know one of the angles formed when two lines intersect, we know that the angle opposite it, the vertical angle, has the same measure.

We also know that the angle beside it, that forms a linear pair, will be supplementary with it (add to 180); this means we can find its measure by subtracting from 180.

The remaining missing angle will be the same as this supplementary angle, since they are vertical angles.

introduction, methodology, results, discussion

step-by-step explanation:

an observational study is one which consists of actual observation to record data and then analyse the data.

there are a number of factors that should be analyzed before starting an observational study.

the main four factors are:

i) introduction:   this should be analysed to check whether the purpose of the study is correctly established and the data recorded are appropriate for the study

methodology:   the method of collecting the data, such as whether randomly selected, and whether sample size matches with the population to be studied, whether questions asked are easy to answer by common men, etc.

results: then results such as summary of data with comments should be studied thoroughly

discussion:   the last is the discussion, this can be either by management people or persons who are all interested , etc.

step-by-step explanation:

given perimeter: 28cm

length: 9cm

atp,

2(l+w)=p of the reactangle

2(9+x)=28

18+2x=28

2x=28-18

x=10/2

x=5

therefore width is 5 cm