## chloed18 one year ago help me please

1. chloed18

the sides of the triangle at right are formed by the graphs of 3x + 2y = 1, y = x -2, and -4x + 9y = 22. Is the triangle isosceles? How do you know?

2. campbell_st

well this is a difficult question. you can Use some graphing software or a site like https://www.desmos.com/calculator to graph the lines.This will help you get an idea of the look of the triangle and then make a decision about the likely sides that could be equal. 1. find the points where each pair of lines intersect... 2. find the distance between any 2 vertices... and trying to find 2 sides with the same lengths An alternate method is to find the slope of each line and then find the angle between 2 lines If you can show 2 angles are the same then the triangle is isosceles The formula for the angle between 2 lines is $\tan(\theta) = \frac{m_{1} - m_{2}}{1 + m_{1} \times m_{2}}$ so depending on what you know the choice is yours Hope it helps