The radius of a circular clock is 10.5 inches. Which measurement is the closet to the measurement of the circumference of the clock in inches. A.33

B.132

C.66

D.346

C:  66 in.

Step-by-step explanation:

The circumference formula is C = 2(pi)(r).  Here, r = 10.5 in.  Thus, the circumference of the clock to the nearest inch is:

2(3.14)(10.5 in) = 65.94 in, which rounds off to C:  66 in.

last option

step-by-step explanation:

given that δdef is right and isoceles,

assuming that side df is the hypotenuse means that de an ef are the other 2 sides that intersect at 90° and are of equal length.

because they are of equal length, we can say that they are congruent

because they intersect at 90°, their slopes must be opposite reciprocals.

only the last option satisfies these conditions.