Question

Mia plans to cover a portion, ADC, of a collage with two triangular pieces of cardboard. She cuts out the first piece of cardboard BCD, as shown below.



What is the length of side AB of the second piece of cardboard, ABD, which Mia has to cut?

23.1 cm

34.6 cm

11.5 cm

19.3 cm

Answer 1

you know how to use sohcahtoa?

Answer 2

umm i think so.. sin = opposite/hypotenuse
cos= adjacent/hypotenuse and tan= opposite/adjacent
i know how to use them but it only gives one side length

Answer 3

if you do use it to find BC and AC then get AB

Answer 4

yea that's right. in this case you are given adjacent side = 20, you only need to find the opposite side

Answer 5

but i only have 1 side length.. thats what i dont understand how can i solve for it with only one side length

Answer 6

so the adjacent side will be one of the answer choices? then what?

Answer 7

for BC tan 30 = BC/DC
for AC tan 60 = AC/DC

Answer 8

so it would be 34.6?

Answer 9

??

Answer 10

woops sorry went afk. i got 23.1

Answer 11

its okay. umm can you explain it step by step how you did it?

Answer 12

tan 30 = BC/20
BC = 20 tan 30 = 11.6

tan 60 = AC/20
AC = 20 tan 60 = 34.6

AC - BC = 23