Ascientist wants to use a model to present the results of his detailed scientific investigation.

why would a model be useful?
because the model makes the concepts easier to understand
because the model is easy to put together and to use
because the model prevents other scientists from asking questions
because the model requires the audience to pay full attention to it

Because the model makes the concepts easier to understand

Step-by-step explanation:

It's a common task in scientific world present the results of an investigation to the community. To do that, they make congresses, symposiums, conferences, et cetera. The objective of the scientist is to have a clear and easy to understand explanation.

c.   x=2.4cm

step-by-step explanation:

similar triangles are triangles which have the same shape but not the same size. this means their angle measures are equal but their side lengths are not instead they are proportional. to solve, we will set up a proportion and solve.

a proportion is two equal ratios set equal to each other. we form the ratios by finding corresponding sides (sides which match to each other on both triangles by their position). out ratios will be one side of the small triangle over the corresponding side on the big triangle as shown below:

.

to solve the proportion, we'll cross multiply by multiplying numerator with denominator across the equal sign.