For one of the triangular sides, 2.6 x 4 = 10.4 divided by 2 = 5.2
Other triangle; 2.6 x 3 = 7.8 /2 = 3.9
Rectangular side in front; 6.5 x 3 = 19.5
Back; 6.5 x 4 = 26
Base; 6.5 x 2.6 = 16.9
Answer: For the surface area it is 74.6 (SUPER SORRY IF THIS ISNT RIGHT OMG)
11: 4,874 > 4,784 > 4,687
12: 8.09 > 8.057 > 8.023
13: 15.820 > 15.280 > 15.000
14: 43,628 > 40,628 > 34,628
15: 395.050 > 395.009 > 395.005
