In a triangle, there are at most acute angles, right angles, obtuse angles and at least acute angles

In a triangle, there are at most acute angles, right angles, obtuse angles and at least acute angles

In a triangle, there are at most 3 acute angles, 1 right angle, 1 obtuse angle and at least 2 acute angles

A triangle has several right angles, several acute angles and several obtuse angles

There is a right angle, an obtuse angle and two acute angles

Two angles of a triangle are acute, so the other angle must be obtuse? Is this my blind spot --? What if both acute angles are 89 degrees? Aren't all sharp angles as long as ＜ 90 °

Of course not. It's also possible that all three are acute angles

Sum of two acute angles of an obtuse triangle () A. Greater than 90 ° B. Less than 90 ° C. Equal to 90 °

Because the sum of the internal angles of a triangle is 180 degrees, one of which is greater than 90 degrees,
So the sum of the remaining two acute angles is less than 90 degrees;
Therefore: B

The sum of the two acute angles of an obtuse triangle is greater than 90 °______ (right or wrong)

One of the obtuse triangles is an obtuse angle, i.e. greater than 90 °,
Because the sum of the internal angles of the triangle is 180 °, the sum of the degrees of the other two angles must be less than 90 °
So the answer is: ×．

If one of the angles of a triangle is obtuse, the other two are acute

This is a true proposition
For example: known Δ In ABC, ∠ a ＞ 90 °. If at least one of the other two angles is greater than or equal to 90 °, such as ∠ B ≥ 90 °, it must be
∠A+∠B+∠C＞180°
This contradicts the fact that the three internal angles of a triangle are equal to 180 °
So the other two corners must be acute
(the above uses the method of counter evidence)