Question

a triangle has an area of 85 cm2. if two of the sides are 18 and 11 what is the third side?

Answer 1

\[A = 1/2 bh \]

Answer 2

...

Answer 3

a can't be equal to 11

Answer 4

Let me know what you get

Answer 5

If area = 85 and
area = .5 * b * h
If base = 18 then height =
85 / (18*.5)
height = 9.4444444444

Using Heron's formula,
area = square root (s • (s - a) • (s - b) • (s - c))
where s = semi perimeter (lengths of all 3 sides divided by 2)
area^2 = s • (s - a) • (s - b) • (s - c)
85^2 = s • (s - 18) • (s - 11) • (s - c)
7,225 = s^2 - 18s * s^2 -11s -cs +11c

If you could solve for 'c' it would equal 15.5555555555555

Answer 6

a is 11, b represents the whole line segment.

Answer 7

wait guys pause for a sec srry, is tht higher level maths

Answer 8

Use Heron's formula
sides = 18, 11 and 15.555555555555555555555
s = semi-perimeter = (18 + 11 + 15.5555555555)/2
s = 22.2777777778


area = square root (s • (s - a) • (s - b) • (s - c))
area = square root (22.2777777778 * (22.2777777778 -18) * (22.2777777778-11) * (22.2777777778 -15.55555555555)

area = sq root (22.2777777778 * * 4.2777777778 * 11.2777777778 * 6.7222222222)

area = sq root (7,224.8109186922)
area = 84.9988877497

Answer 9

Actually its really simple stuff @Adi3, its just simple manipulation of the Pythagoras theorem and the area of a triangle with a little bit of imagination and visualization :)
I find it helpful to form a quick mental picture of what's going on before I start, and if need be I might jot it down on a piece of paper.

What do you say @wolf1728?

Answer 10

15.56 is my answer and yes it's correct thankss.. i was actually esay i just drew it incorrectly . :D :D thank you all especially @Javk