In the diagram, AB= DC and AC= DB. Why does DBC = ACB?

AB = DC                         Given

AC = DB                         Given

BC = BC                         Reflexive property

△ACB = △DBC             SSS

m∠DBC = m∠ACB       CPCTC    

Step-by-step explanation:

Reflexive property basically means that something is congruent to itself

SSS means that if all 3 sides of 2 triangles are congruent, the triangles are congruent

CPCTC means C.orresponding P.arts of C.ongruent T.riangles are C.ongruent

meaning because the triangles are congruent, all the corresponding sides and angles are also congruent

step-by-step explanation:

there is a formula i can give you:

it is r^2*n*sin(360/n) divided by 2 where r represents the "radius" and n is the number of sides.

plug them in:

(10sqrt(3))^2*6*sin(360/6) divided by 2

100*3*6*sin(60) divided by 2

900*sin(60)

900*sqrt(3)/2

450*sqrt(3)

approx is 779.4 cm^2

step-by-step explanation:

de-gf

hj=3x+20

ji=15x-64