On lines a and b, the points a1, a2, a3 and b1, b2, b3 are selected, respectively, as lines a1b1 and a3b3 are parallel. As A2a3 is 5cm, b1b2 is 6cm, b2b3 is 4cm, find a1b1

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:

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