A right-angled triangle must have acute angles at the other two vertices because those two angles have to be less than 90 degrees.
Every triangle must have at least two acute angles. The third one can be acute, right (90 degrees), or obtuse.
No. In fact, if one of the angles is not acute (a right angle or obtuse), the other two must be acute.
Just the one and the other two angles must then be acute angles
A right angled triangle has one angle that is 90 degrees. The other two must be acute and may (but need not) be equal to one another. An acute triangle has all its angles less than 90 degrees. They may be all the same, two of them the same or all different. An isosceles triangle has two angles the same (and hence acute). The third angle can be acute, right or obtuse. A scalene triangle has three unequal angles. Two of them must be acute but the third may be acute, right or obtuse.
The sum of two acute angles of a right triangle must equal 90 degrees.
Such a triangle would presumably have one right angle, and two acute angles. A right angle has a measure of 90 degrees; an acute angle has a measure of less than 90 degrees. Since both of the other two angles in a right triangle must be acute angles, you'd think at first that every right triangle must be a right acute triangle. But when you go and look up the definition of an "acute triangle", it turns out to be a triangle in which all three angles are acute. So the fact is that there's no such thing as a right acute triangle, because the 90-degree angle in a right triangle is not acute.
A right-angled triangle must have acute angles at the other two vertices because those two angles have to be less than 90 degrees.
No, acute triangles must have all angles less than 90 degrees.
Every triangle must have at least two acute angles. The third one can be acute, right (90 degrees), or obtuse.
No. In fact, if one of the angles is not acute (a right angle or obtuse), the other two must be acute.
In a right triangle, one of the angles is already given - 90 degrees. Since the angles of a triangle must add up to 180 degrees, the other two must always add up to 90, so that after you add the right angle, the sum is 180. So both of the other angles have to be less than 90. That is, they both must be acute. So there can be NO obtuse angles in a right triangle. There are EXACTLY two acute angles in a right triangle.
Just the one and the other two angles must then be acute angles
Only if the right triangle contains a 90 degree angle and 2 acute angles that add up to 90 degrees
Actually, you cannot conclude anything this way, at least not in regular geometry. For instance, in a "perfect triangle," all 3 angles are acute. In a right triangle, one is a right angle and the other two are acute. It is also possible to have an obtuse angle and two acute angles. The thing is, the 3 angles must add up to 180 degrees.
No, an acute triangle must have all 3 angles under 90 degrees. A triangle can have an acute angle and still be a right triangle or an obtuse triangle.
In plane geometry at least two angles must be acute in a triangle.