An isosceles triangle.
1080 degrees
The interior angles measure 360 degrees.
Each angle has a measure of 120 degrees
You could estimate. If it is not right, it is between 90 degrees and 0 degrees. If it is between right and straight angles, it would be between 90 degrees and 180 degrees. You can sort of figure out roughly where each and measurement was.
20 degrees
If all of the angles add to 180 degrees the figure is a triangle. * * * * * That is if they form a plane figure. Angles that add to 1890 degrees are called supplementary angles.
Triangle or Pyramid
a rhombus
You might be able to figure this out for yourself, based on the following information:* The angles of a triangle must add up to 180 degrees. * A right angle has a measure of 90 degrees.
If interior measure means interior angles, their sum is 360 degrees. Also, whether the figure is convex is irrlevant.
Total of exterior angles of a plane figure is always 360 degrees so 360/20 = 18 degrees. Alternatively interior angles of n sided figure always total (2n -4) right angles. In this case n = 20 so total interior angles = 36 right angles ie 3240 degrees and each angle = 3240/20 ie 162 degrees. Subtracting this from 180 gives 18 degrees. QED
The angles have the same measure. In the reflection the order of the angles are changed from clockwise to counterclockwise.