If δabc is congruent to δdef, which statement must be true?

a.
line bc is congruent to line de
b.
∠a is congruent to ∠d
c.
∠bac is congruent to ∠def
d.
line ab is congruent to line ef

The position of a moving particle is given by the position function: f(t)=-9t-t^2-0.2t^3+0.1t^4 0 a. at what time does the particle reverse direction? b. when is the displacement positive? (round one decimal place and answer in interval notation) c. when is the displacement negative? (round one decimal place and answer in interval notation) d. when is the particle’s acceleration positive? (round one decimal place and answer in interval notation) e. when is the particle’s acceleration negative? (round one decimal place and answer in interval notation)

Aadc is formed by reflecting aabc across line segment ac, as shown in the figure. if the length of ac is 4 units, the area of aadc is square units.

When i'm with my factor 5, my prodect is 20 .when i'm with my addend 6' my sum is 10.what number am i