The angles in a triangle are 100, 40, and 40 degrees. Classify the triangle by its angles and sides. A. Right isosceles
B. Right Scalene
C. Obtuse scalene
D. Acute isosceles
E. Acute scalene
F. Obtuse isosceles

F. Obtuse isosceles

Step-by-step explanation:

Since we have an angle that is 100 degrees, we have an obtuse angle

We have two angles that are 40, which means we have two sides that are equal length, because two angles have the same measure.  That means it is isosceles

The triangle is an obtuse isosceles

both equations and proportions are better.

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.