Which shape has the right angles and side that are the same length?

The square (3rd option)

Step-by-step explanation:

Squares have 4 right angles, and has 4 sides of equal lengths.

Just by looking at the other answer choices, you can tell that the 1st option, 2nd option, and 4th option aren't correct because though some may seem that they have right angles, their sides do not all the look the same length.

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.