Right Obtuse And Acute Triangles. Skip to content ixl learning learning (obviously, only a single angle in a triangle can be obtuse or it wouldn’t be a triangle.) a triangle must be either obtuse, acute, or right.

If we add up the three angles of any triangle, they always equal 180 °. In respect to this, how do you know if an obtuse is acute or right? For the obtuse, right angle and acute triangles cosine of the angle opposite to the longest sides will be negative, 0 and positive, respectively.

An Equilateral Triangle Is An Acute Triangle. In an equilateral triangle, all the sides of a triangle are of equal length. An acute angle is an angle that is between 0° and 90°.

An acute triangle may be equilateral , isosceles, or scalene. Therefore we can determine that each angle is. If all sides of a triangle are the same length and all angles are 60 degrees, can the triangle be called both an acute triangle and an equilateral.