Find the lengths of all three sides of the triangle.

Complete the solution of the equation. find the value of y when x equals to 6 4x+y=20

The figure shows triangle def and line segment bc, which is parallel to ef: triangle def has a point b on side de and point c on side df. the line bc is parallel to the line ef. part a: is triangle def similar to triangle dbc? explain using what you know about triangle similarity. part b: which line segment on triangle dbc corresponds to line segment ef? explain your answer. part c: which angle on triangle dbc corresponds to angle f? explain your answer. asap

Given the net of the rectangular prism, what is its surface area?