What is ed? sorry i need these for my study guide and i was absent

  ED = 8

Step-by-step explanation:

ΔAED ~ ΔDEC so the corresponding sides are in proportion:

  DE/DC = AE/AD

  (x+4)/6 = (2x +4)/9

  3(x +4) = 2(2x +4) . . . . multiply by 18

  3x + 12 = 4x +8 . . . . . . eliminate parentheses

  4 = x . . . . . . . . . . . . . . . add -8-3x

  ED = x +4 = 4 +4

  ED = 8

b. an equilateral triangle inscribed in a circle

step-by-step explanation:

we are given the figure of two circles having a triangle inside.

now, we know that,

"when a figure is lying inside an another figure, then the outside figure is known as circumscribed figure and the figure lying inside is referred to as the inscribed figure".

as we see that, the circles are containing the triangle completely.

thus, the circles are the circumscribed figures and the triangle is the inscribed figure.

hence, we get, 'an equilateral triangle is inscribed in a circle'.

c is the correct answer

step-by-step explanation: