Well the area of a trapezoid is defined by the following formula:
A =

where b₁ and b₂ are the bases of the trapezoid and h is the height of the trapezoid.
Let's plug in what we know into this formula:
h = 7 the perpendicular distance between the two bases
b₁ = 15 the shorter parallel side
b₂ = 25 the longer parallel side made up of 4 + 15 + 6
so, A =

This is in square units of measure of course, so 140 in²
<span>(a.)
Let's say α is the angle that subtends from the top of the screen to horizontal eye-level.
Let β be the angle that subtends from the bottom of the screen to horizontal eye-level.
tanα = (22 + 10 - 4) / x = 28/x
α = arctan(28/x)
tanβ = (10 - 4) / x = 6/x
β = arctan(6/x)
Ɵ = α - β
Ɵ = arctan(28/x) - arctan(6/x)
(b.)
tanƟ = tan(α - β) = (tanα - tanβ) / (1 + tanα tanβ)
tanƟ = (28/x - 6/x) / [1 + (28/x)(6/x)]
tanƟ = (22/x) / [1 + (168/x²)]
tanƟ = 22x / (x² + 168)
Ɵ = arctan[22x / (x² + 168)]</span>
<span>A whole number greater than 1 could be 2,3,4,5... And so on. A fraction greater than 1 is any fraction where the top number (numerator) is greater than the bottom number (denominator) for example 7/5</span>
Based on the information given, it can be noted that the problem with the research is the problem of validity.
<h3>
Problems with validity.</h3>
It should be noted that in a research, a problem with validity takes place when there's a lack of reliability of the independent variable.
Also, it is a result of lack of representativeness of the independent variable and a lack of impact of the independent variable.
In this case, the researcher sets out to measure drug use on US college campuses by asking a representative sample of undergraduates whether they are currently receiving federal grants or loans. It should be noted that the question asked doesn't relate to the research.
In conclusion, there's a problem with validity.
Learn more about researches on:
brainly.com/question/25257437