What is the percent of decrease from 75 to 21?

The midpoints of the sides of the large square are joined to form a smaller square. what is the area of the smaller square

Aladder that is 20ft long is leaning against the side of a building. if the angle formed between the ladder and the ground is 75 degrees how far is the bottom of the from the base of the building?

Ihave a triangle with a 60 degree angle. lets use d for that angle. what are the values of e and f if d is 60 degrees? and what do you notice about the values of e and f?