 Here we have one more problem dealing with the base angles in an isosceles triangle I know it's isosceles because these little congruence marks exist with isosceles triangles base angles are congruent those are the base angles because That third side would be the base and So since base angles are congruent, I know that those angles must equal each other 3x minus 5 Must equal 5x minus 43 So then let's uh, let's solve for Excel. I'll subtract 3x from both sides add 43 to both sides and Lastly divide by 2 on both sides So then there's one last little little thing with this particular problem. We found x Did it? Did it and now we need to classify the triangle by its angles so it's either a cute right or obtuse So let's take this value of x and substitute back into the angles k and angle m So we need 3 times 19 minus 5 and so that means angle k is 52 degrees Likewise angle m is 52 degrees Because base angles are congruent and so this third angle Angle L well right now it's unknown, but because of the triangle sum theorem. I know that the measure of angle L plus two angles that are 52 degrees Must add up to 180 degrees and so we can solve for the measure of angle L so this angle is 76 degrees so each of the three angles 52 52 and 76 all of those are acute angles and so we can classify this triangle as an acute triangle