What number and what percent describe the probability of a curtain event? What number and what percent describe the
probability of an impossible event

the figure is a concave pentagon.

step-by-step explanation:

in mathematical context, a pentagon is a flat, two-dimensional closed shape (polygon) with 5 straight sides and 5 angles.

now a pentagon is said to be concave if one or more corners bend inwards and at least one of its angles is 180 degrees or more than 180 degrees.

in the given figure, we can see that we have a corner which is bending inwards and an angle which is clearly greater than 180°. therefore, it is a concave pentagon.