Write an expression in fully factored form for the shaded area?

41/2 - 1 1/3 what is the answer as a fraction?

In the figure below, segment ac is congruent to segment ab: triangle abc with a segment joining vertex a to point d on side bc. side ab is congruent to side ac which statement is used to prove that angle abd is congruent to angle acd? segment ad bisects angle cab. triangle acd is similar to triangle abd. segment ad is congruent to segment ac. angle cab is congruent to angle cba.

Average acceleration: i have no idea how to do this.