Work out the length of DB in the diagram below

How many zeros does the function f(x)=4x3-x2+1 have

1) in triangle the, what is the measure of angle t (in degrees)? 2) in triangle bat, the measure of angle b is 66∘, and the measure of angle t is 77∘.what is the measure of the exterior angle at a (in degrees)?

Find the area of the unshaded square