Here's the question you clicked on:
Fosterthepeople
PTG has side lengths of 12 cm, 25 cm, and 19 cm. Which type of triangle is PTG? right acute obtuse isosceles
for isosceles 2 sides are the same. for a right triangle a^2+b^2=c^2 where a and b are the legs and c is the hypotenuse. so that's two things to check...
once you've done that it's easy to know what kind of triangle it is.
|dw:1324940623672:dw| use cos rule to find the angles
you actually don't need the angles Just check the two shorter sides a and b against the larger side c: if\[c^2=a^2+b^2\]the it is a right triangle. If\[c^2>a^2+b^2\]it is an obtuse triangle. If\[c^2<a^2+b^2\]it is an acute one. It is only isosceles if\[a=b\]
i got obtuse is that right?
that's what I got :)