Question

Use the image to answer the question.

Solid triangle upper A upper B upper C and dotted triangle upper A upper B upper D are plotted in quadrant 1 of a coordinate plane. The altitude of vertex upper D is drawn as a dotted line that extends from upper D to side upper A upper B.
▶Click for Long Desc

The area of triangle ABD
is 13
the area of triangle ABC
. Find y, the missing coordinate of vertex D
.

(1 point)
Responses

y=4.1
y equals 4.1

y=2.1
y equals 2.1

y=19.2
y equals 19.2

y=1.3
y equals 1.3
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Answer 1

I can’t see the diagram from that description — could you either upload the image or type the coordinates of A, B, C (and the given coordinates of D except y)?

Hint/formula so you can check while you upload: ABD and ABC share the same base AB, so their areas are proportional to their altitudes to AB. If hC is the altitude from C to AB and hD is the altitude from D to AB (which equals the y you want if AB is horizontal), then

area(ABD) / area(ABC) = hD / hC.

So hD = (area(ABD) / area(ABC)) * hC.

Once you send the picture or the coordinates I’ll compute y and pick the correct choice.