The triangular prism has 5 faces; two triangle faces and three rectangular faces.
We can find the area of one of the triangle faces by doing ((base * height) / 2). In this case, it would be ((2 * 2) / 2), which of course would equal 2"². Multiplied by two for the two triangles, which would be 4.
To find the area of one of the rectangles, we do (length * base), which would be (5 * 2) in our case, giving us 10. Multiply by 3 for the 3 faces, and we got 30"².
30 + 4 = 34"²
10 divided by 2 minus 1 equals 4
The scneario here expressed is an aritmetic sequence because it can be explained like this:
<span><span><span>a1</span>=35
</span><span><span>an</span>=<span>a<span>n−1</span></span>+<span>17
So all the variables can fit in and will be better explained than a geometric sequence in which you need a common ratio and that is not needed in this case</span></span></span>
Check the picture below.
let's recall that a straight-line has 180°, and that sum of all interior angles in a triangle is also 180°.