Question

Can someone help me with a geometry proof?

Answer 1

B is the midpoint of line DC and line AB

Answer 2

AB is perpendicular to DC

Answer 3

prove the triangles are congruent

Answer 4

I would first label the parts that are equal to each other (based on the "givens")
I would list the different ways you can prove two triangles are congruent.

can you do those 2 things ?

Answer 5

I did I'm stuck though...

Answer 6

let me send what i did

Answer 7

ok so far. But can you
list the different ways you can prove two triangles are congruent. ?

Answer 8

SAS SSS is what we've been using

Answer 9

there is also ASA

but look at your two triangles. Can you show SAS or SSS (based on what you labeled )
?

in other words, for SAS, can you list a side, an angle, and a side (in that order)
that match up with the side , angle and side of the other triangle ?

Answer 10

I can't, that's why I'm stuck

Answer 11

what parts can you show are congruent ?

Answer 12

line DB and BC Angle ADB and Angle ABC

Answer 13

*ABD

Answer 14

so if you wanted to use side angle side
what is missing , that you need ?

Answer 15

a side

Answer 16

not any side. which side ?

Answer 17

AD and AC

Answer 18

side AD would not work.

you want to list a side-angle-side in that order (no gaps)

example
side AD,
then angle ADB
then side DB

but we don't know about angle ADB

try again.

Answer 19

oh ok, side AB

Answer 20

in the left triangle we have
side-angle-side : side DB, angle ABD, side AB
for the right triangle we have
side CB, angle ABC, side AB

Answer 21

would that count as the reflexive property for the proof?

Answer 22

now if you could show that AB equals itself, you are all set.

YES! reflexive property

Answer 23

ok, thank you!!!

Answer 24

you need to add in
AB=AB reason: reflexive property
and in the last line,
for the reason, say SAS

Answer 25

I did, thank you