If a triangle on a coordinate plane is composed of points A (0,0), B (5,3) and C (a,0), find a. (Assume the angle ABC is a right angle) How do you find a? Help!
2007-01-24 20:52:11 · 7 answers · asked by Ken 2 in Science & Mathematics ➔ Mathematics
I tried solving it this way...please check if its correct
First, I created a smaller triangle from points A, B, and a point on the x-axis directly below B, assume that this new point is D.
tanA=3/5 [this i got from the coordinates of B]
A=31 degrees
Then, moving on to triangle ABC
cos31=((sqrt(34))/a)
[sqrt(34) is from using the pythagorean theorem on the small triangle ABD and a is the length of AC]
a=(sqrt(34))/(cos31)=6.8
Is this correct?
2007-01-24 21:37:10 · update #1
If you drop a perpendicular from point B to the x-axis, you meet the x-axis at D(5,0). You have now divided the original triangle ABC into two similar triangles:
ABD and BCD
AD = 5
BD = 3
AD is the longer leg of the first triangle
BD is the shorter leg of the first triangle
and the longer leg of the second triangle
DC is the shorter leg of the second triangle.
Therefore
BD/AD = DC/BD
3/5 = DC/3
9/5 = DC
AC = AC + DC = 5 + 9/5 = 6 4/5 = 6.8 = a
Your answer is correct.
2007-01-24 22:55:58 · answer #1 · answered by Northstar 7 · 0⤊ 0⤋
If a triangle on a coordinate plane is composed of points A (0,0), B (5,3) and C (a,0), find a. (Assume the angle ABC is a right angle) How do you find a? Help!
Since the triangle has 90 degree angle at point B, then 90 degrees from line A-B would be line C. Draw line A, B, and then draw a line 90 degrees from AB, and extend the line across the Y Axis
2007-01-25 04:59:58 · answer #2 · answered by antsam999 4 · 0⤊ 0⤋
a = 5
2007-01-25 05:02:21 · answer #3 · answered by bipabeop 1 · 0⤊ 2⤋
a=5
since it is a right angle, u just need to plot point B on the graph paper and draw a straight line to the x-axis since the y-coordinate for C is 0. when the straight line crosses with the x-axis, u will get your point C and its coordinates which should be C(5,0)
2007-01-25 05:09:50 · answer #4 · answered by ichigo 1 · 0⤊ 1⤋
Its quite an easy question...
Use distance formula to find the three sides and use Pythagoras theorem
or..
Find slopes of the base and perpendicular(m1 & m2)
m1 * m2=-1
Wasn't that easy...
2007-01-25 06:54:53 · answer #5 · answered by neeraj_agarwal_1990 1 · 0⤊ 0⤋
Draw a picture.
2007-01-25 04:56:23 · answer #6 · answered by Anonymous · 0⤊ 2⤋
i think your answer is the right answer
2007-01-25 06:00:34 · answer #7 · answered by fair m 1 · 0⤊ 0⤋