What is the area of the triangle in the diagram?

B.

Step-by-step explanation:

the area of a triangle is

Area = baseline × height / 2

the baseline can be any of the 3 sides.

the height is then the perpendicular connection from the corner point opposite of the chosen line to the chosen line.

in this example the easiest approach would be to pick (x1,y1) to (x2,y1) as baseline, and the height would then be the piece of the y-axis from (0,0) to the baseline.

so, how long is the baseline ?

we need to calculate the difference between the coordinates of both corner points.

we have here an easy case, as both points have the same y value, so we only need to look at the difference in x.

baseline = x2 - x1

and the height is here simply (because of the special case) the difference of the baseline from (0,0) on the y-axis

height = y1

therefore, the area of the triangle is

Area = (x2-x1) × y1 / 2 = 1/2 × y1(x2-x1) = solution B

if the corner points and height are not so nicely aligned with the coordinate axis, then we need to calculate the distances by using Pythagoras to determine the "Hypotenuse" of the triangles created by the differences of the individual coordinates.

in our example

((x1,y1) to (x2,y1))² = (x2-x1)² + (y1-y1)² = (x2-x1)² + 0 = (x2-x1)²

and therefore

(x1,y1) to (x2,y1) = (x2-x1)

and we are back to our original solution.

the clues that signal the reader should change tone are the punctuation marks, the grammatical signs. for example, the quotation marks at the beginning of something someone else said literally or the exclamation marks.

the tone of the first line of dialogue until "gettysburg" is a kind tone, a tone of advise. the narrator is trying to the other person in doing something he or she obviously is finding hard to do by giving a piece of advise and bringing up a memory of a successful similar case.

the clue that the reader understand how to read the word "bang" is the exclamation mark. it gives the word a surprise tone, a strong accent.

the best tone for reading the word "bang" is an exciting tone, a surprise one, even a loud one.

the words that should be read with a formal tone are the ones that give factual information. the sentence: mister lincoln couldn't think of anything to say at the gettysburg" gives information about an event and it needs to be read formally, also, when the narrator wants to transmit calmness, a formal and slow tone is needed, because people also transmit messages with the vibrations of our voices and tones.

step-by-step explanation: