44 / 80 Marks 20%
The diagram shows triangle ABC.
ADC and BED are straight lines.
AB = 12.2 cm Angle ADB = 90°
CD = 5.8 cm
Angle ABD = 38°
BE: ED = 3:1
12.2 cm
E
38
B.
D
Work out the size of angle DCE.
Give your answer correct to 1 decimal place.
You must show all your working.
5.8 cm
+
С
Total marks: 4

false

step-by-step explanation:

false.   two legs of the trapezoid would be congruent, but the other two would not.   were all the legs congruent, then we'd have a square; were the 2 shorter sides congruent and the 2 longer sides also congruent, we'd have a rectangle.

geometry: triangles

solvers

lessons

answers archive

call the larger triangle abc

then the smaller triangle cde is similar to abc (all angles are equal, aaa).  

ab is the side that is 36, and we wish to find de, the side corresponding to ab

area_cde = area_abc - area_cde --> area_abc / area_cde = 2

let x=length of de

ratio of areas = (ratio of sides)^2

+2+=+%2836%2fx%29%5e2+

+2+=+1296%2fx%5e2+

++x%5e2+=+1296%2f2+=+648+

25.45584