Use the patterns you have investigated to determine the missing side lengths of each of the triangles below. Do not use a calculator.

1. 

   Hint (a):

   $12$ and $20$ are both multiples of $4$.

2. 

   Hint (b):

   This triangle is half of a square.

3. 

   Answer (c):

   $24$ feet

4. 

   Hint (d):

   This triangle is half of an isosceles triangle.

   Partial answer (d):

   The short leg is $10$ m.