81, 84 and 87. And 90 if you want to count that
There are 3 such numbers: 30, 60, 90.
81, 84, 87.
18, 36, 54, 72, 90
False because angles greater than 0 but less than 90 degrees are acute angles
72
81,84,87,90
Nine.
66, 72, 78, 84, 90, 96.
81, 84 and 87. And 90 if you want to count that
There are 3 such numbers: 30, 60, 90.
1, 2, 3, 4
81, 84, 87.
The multiples of 5 that are also multiples of 6 are multiples of their LCM. The LCM of 5 and 6 is 30, so the question becomes which multiples of 30 are less than 100? The solution is the numbers: 30, 60, 90
81, 84, 87.
The multiples of 10 that are less than 125 are 20, 30, 40, 50, 60, 70, 80, 90, 100, 110, and 120.
This is a triangle in which all of the angles are less than 90°.