How do I figure out this triangle problem?

Question

Decide whether or not the points are the vertices of a right triangle.

(-2,0), (4,2), (8,-10)


I don't need the answer, just how to work it out.

Answer 1

The slopes are
AB =1/3
AC= -1
BC= -12/4=-3
so AB and BC are perpendicular

Answer 2

Do not rely on an instrument like a protractor! You can tell without even drawing the triangle.

Find the slopes of all three sides. Do this by computing rise over run. For example, the slope of the second and third points (4,2) and (8,10) is

(10 - 2) / (8 - 4) = 8/4 = 2

So you'll have three different slope values. Let's call them m1, m2, and m3. If the triangle is a right triangle, exactly two of these slopes will be perpendicular to each other -- that's where the right angle is! Two slopes are perpendicular if one is the negative reciprocal of the other. So you'll have either

m1 = -1/m2

or

m2 = -1/m3

or

m3 = -1/m1

If any of these is true, you have a right triangle.

Answer 3

Yes its is a rt triangle.
The slope of the line from (-2,0) to (4,2) = 1/3
The slope of the line from (8,-10) to (4,2) = -3
Since the two lines have slopes that are negative reciprocals, the two lines are perpendicular. Hence the triangle is a righrt triangle.

Answer 4

I asume you mean right angled? If not sorry I bothered you =P
Draw some axis,
And then plot the points.
Then you can measure the angle and see if its 90 degrees
It's simple if you know what you're doing.
Sorry I don't know what level of mathmatics you are doing to give you a better answer than this.
Good luck (:

Answer 5

try to draw it. does it look like a right triangle? once you draw it, to be 100 % sure you can try to use the pythagoras thearom. if it's true, you got a right triange