Answer:
D
Step-by-step explanation:
Two triangles are congruent if they have the same three sides in proportion and they have exactly the same angles.
If the angles are different, the triangles are not similar.
The original area of a face would be a^2. Now that you added b to the edge, the new area of each face would be (a+b)^2. To find how much the are increased, subtract a^2 from (a+b)^2. 
So the answer is b(2a+b)
You need to do 20 divide by 21 to get a decimal. Then if you multiply the decimal by hundred you should get the percentage.
Answer:
Just as the square root is a number that, when squared, gives the radicand, the cube root is a number that, when cubed, gives the radicand. Cubing a number is the same as taking it to the third power: 23 is 2 cubed, so the cube root of 23 is 2.
Step-by-step explanation:
there i hope you understood
