Question 166150
use the distance formula{{{d=sqrt((x2-x1)^2+(y2-y1)^2)}}}
find the distance between (4,5) and (1,1) distance=5
find the distance between (1,1) and (-2,5) distance=5
find the distance between (-2,5) and (4,5) distance=6
a triangle with 2 congruent sides is an isosceles triangle
next, bisect the angle where the two congruent sides meet and draw a straight line forming a 90 degree angle with the third side.
the new triangle that this forms has one side with length of 3, hypotenuse of 5 and an unknown length.  Use the Pythagorean Theorum {{{A^2+B^2=C^2}}} to find the 3rd side.  We find that it is 4.
Then use the A=1/2BH formula to find the area of the triangle.
click on my name to go to my website, once there go to the "Solutions" page and there is a pdf file so you can see how this looks when drawn out.
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Hope this helps!
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MRperkins