Posted by vaughn on Monday, January 7, 2013 at 1:46pm.
Find the bisectors of the interior angles of the triangle whose sides are the line 7x+y-7=0, x+y+1=0 and x+7y-4=0.
Please I really need help. I do not know how to do this problem
- geometry - Steve, Monday, January 7, 2013 at 2:14pm
It really helps to draw a diagram, so you know which three angles you're dealing with. Label the three lines L1,L2,L3 in order.
First, get the slope of each line:
Now convert those slopes to angles, measured counter-clockwise from the x- axis:
L1: θ = 98.13°
L2: θ = 135.00°
L3: θ = 171.87°
Now, the angle bisector is the average of the two angles made by the lines:
B1: (L1+L2)/2 = 116.57° tan = -2
B2: (L2+L3)/2 = 153.43° tan = -1/2
B3: (L1+L3)/2 = -135.00° tan = 1
Now you need the intersections of the lines:
P1(L1=L2): (4/3, -7/3)
P2(L2=L3): (-11/6, 5/6)
P3(L1=L3): (15/16, 7/16)
Now we have a point-slope for each angle bisector:
B1: (y+7/3) = -2(x-4/3)
B2: (y-5/6) = -1/2 (x+11/6)
B3: (y-7/16) = 1(x-15/16)
B1: 6x+3y-1 = 0
B2: 6x+12y+1 = 0
B3: 2x-2y-1 = 0
Answer This Question
More Related Questions
- Analytic Geometry - Find the bisectors of the interior angles of the triangle ...
- GEOMETRY ONE QUESTION PLEASE HELP!!!!! - Where is the circumcenter of any given ...
- Geometry - Please answer at least one . PLEASE 1. Triangle XYZ has a right ...
- geometry - In a triangle ABC , the internal bisectors of angles B and C meet at ...
- Math - line BC is one side of a regular n-gon. The sides next to line BC are ...
- Geometry - 1) In the diagram above, line a is parallel to line b. Which theorem...
- Math! Please check! - When constructing the circumcenter and circumscribed ...
- Geometry - The measure of an exterior angle of a triangle is 120. the interior ...
- Geometry - A right triangle has exterior angles at each of its acute angles ...
- Geometry - How do you prove that the sum of distances to a point from the ...