We know the width of the rectangle in the middle of the trapezoid is 24 (from the top of the image), so we can subtract that from the bottom width of the trapezoid to get the combined length of the bottom of both triangles.

Since this is an isosceles trapezoid, both triangle bases are the same length, so we can cut this value in half to get the length of  and
 and 

Finally, we can use the Pythagorean Theorem to find the length of  :
:





 
        
             
        
        
        
60 is the base OK. I think am right
        
             
        
        
        
8. 6m + 3n
11. 8r^3 - r^2
12. 3h^2 + 8
hope this helps !
        
             
        
        
        
Answer:
<h3>
Step-by-step explanation:</h3>
A)answer: A cross section is the two-dimensional shape that results from cutting a three-dimensional with a plane.
B)answer: A cross section is the face you obtain by making a "slice" through a solid object. A cross section is two-dimensional. ... When a plane intersects a solid figure, the cross sectional face may be a point, a line segment, or a two-dimensional shape such as, but not limited to, a circle, rectangle, oval, or hexagon.