Can someone help please AC line ? Maximum 56 points.

18.1 cm

Step-by-step explanation:

Consider a segment parallel to CD and passing through B.

This segment will form a right-angle triangle with A

It's length would be equal to the length of CD (the missing length)

Height of that triangle:

11 - 4 = 7

CD² = 16² - 7²

CD² = 207

CD = sqrt(207)

AC² = AD² + CD²

AC² = 11² + 207

AC² = 328

AC = 2sqrt(82)

Which is roughly 18.1 cm

we have three similar triangles, because each has a right angle and shares an angle.   let's write the angles in order: opposite to short leg, long leg, hypotenuse.

cab similar to bad similar to cbd

or as ratios,

ca: ab: cb = ba: ad: bd = cb: bd: cd

we also know

ac = ad + cd

(ad+cd): ab: cb = ba: ad: bd = cb: bd: cd

(ad+cd)/cb=cb/cd

we have cb=6, ad=5 and seek x=cd.

we reject the negative root and conclude x=4

answer: 4

-60.75

step-by-step explanation:

just add the numbers then put the negative sign on it