Question

Find the missing lengths in the triangle. Round to the nearest tenth if necessary.

a = 7.5 cm, b = 10.6 cm
a = 13 cm, b = 7.5 cm
a = 7.5 cm, b = 13 cm
a = 5 cm, b = 13 cm

Answer 1

i think it was a = 7.5 cm, b = 13 cm
am i right

Answer 2

i think it's c

Answer 3

Zhang you're treating trignometry... right?

Answer 4

it is the half uniform triangle
thus
a=15/2
\[b=15*\sqrt{3}/2\]

Answer 5

@chanh_chung I'm not exactly sure I understand your working... :| you mind explaining what you mean by half uniform triangle? and why you go ahead to say "thus"... how did you arrive at that implication? I'm sort of lost. you're probably right but I just want some clarity :) thanks

Answer 6

yeah so i do i was like what?

Answer 7

so is it C?

Answer 8

ok
we have in uniform triangle ABC
AB=AC=BC
and
angel A=B=C
appli Ptago

h=height of the triangle ABC is
h^2=AB^2-(1/2BC)^2=AB^2-1/4AB^2 (because AB=BC)
=3/4AB^2
thus
\[h=\sqrt{3/4AB^2}\]
\[h=\sqrt{3}*AB/2\]

Answer 9

@chanh_chung is it C?

Answer 10

Zoe do you understand it?

Answer 11

kind of...

Answer 12

yes a=7.5
b=13

Answer 13

oh ok thanks chanh_chung

Answer 14

in the problem
triangle is the half uniform triangle
hence h=height of the triangle ABC is b
and a is 1/2*AB with AB=15