AB = 6 cm, AC = 12 cm Calculate the length of CD.
Give your answer to 3 significant figures.
12 cm
55°
6 cm

12.7 cm

Step-by-step explanation:

We can obtain CB using Pythagoras :

CB = √12² - 6²

CB = √108

CB = 10.39

Using CB,

We can apply trigonometry on triangle BCD to obtain the length of CD

Sin θ = opposite / hypotenus

Sin 55 = CB / CD

Sin 55 = 10.39 / CD

CD = 10.39 / sin 55

CD = 12.68

CD = 12.7 cm

option a is correct.

step-by-step explanation:

scale factor: it is used to find proportional measurements.

proportions means having the same ratio.

scale factor is the ratio of the model measurement to the actual measurement in a simplest form.

or we can say that the ratio of any two corresponding lengths in two similar geometric figures

if the scale factor is more than 1, then it is an enlargement,

if the scale factor less than 1, then it is a reduction.

given the two geometric figure:

by definition of proportions, we have