Diagonal ac divides the trapezoid abcd (with bases ad and bc , ad> bc) into two similar triangles, △abc and △dca. find ac if bc=4 cm and ad=9 cm.

AC= 6 cm

Step-by-step explanation:

It is given that ABCD is a trapezoid

Also AC divides the trapezoid into two similar triangles

ΔABC≈ΔDCA

The ratio of corresponding sides of similar triangles are equal, so we have

now we can take

    ( since BC=4 and AD= 9)

now we cross multiply

   (taking square root )

AC= 6 cm

step-by-step explanation:

i think you should think about the question and not look online.

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