Answer:
3) 162 ft²   ||  4) 38.25 mm² 
Step-by-step explanation:
3)
area of triangle = 0.5 * base * height
                           = 0.5 * 27 *  12
                           = 162 ft²
4) area of triangle = 0.5 * base * height
                               = 0.5 * 8.5 * 9
                               =  38.25 mm²
 
        
                    
             
        
        
        
Since we don't want to use the Pythagorean Theorem on all of these, first we look for some Pythagorean Triples. Its very helpful to know some of the common ones, so here's a list:
3, 4, 5
5, 12, 13
7, 24, 25
8, 15, 17
So we either look for these or a multiple of these numbers.
The last one is the only one that fits because 15, 20, 25 is a multiple of the triple 3, 4, 5 by multiplying all of them by 5. 
Thus, 15, 20, 25 forms a right triangle. 
        
             
        
        
        
bus A takes 25 mins
bus B takes 35 mins
start at 8am
to find =lcm of 25 and 35
LCM of 25 and 35
5 /__25,35
/__5,7
LCM=5×5×7
=175 mins=8hr+175mins=10:55am