Please help! find the surface area of the prism

1. 172 cm²

2. 226.56 cm²

3. 336 cm²

4. 284 cm²

Step-by-step explanation:

which one ? all ?

a surface area of an object is always the sum of the individual shapes areas on its surface.

1. 6 rectangles (length×width)

2 rectangles of 2×8 = 16 cm²

32 cm²

2 rectangles of 2×7 = 14 cm²

28 cm²

2 rectangles of 7×8 = 56 cm²

112 cm²

total : 32+28+112 = 172 cm²

2. 2 triangles and 3 rectangles

2 triangles (baseline × height / 2) = 7.2×4.8/2 = 17.28 cm²

34.56 cm²

2 rectangles 10×6 = 60 cm²

120 cm²

1 rectangle 10×7.2 = 72 cm²

72 cm²

total : 34.56+120+72 = 226.56 cm²

3. 2 triangles (right-angled) and 3 rectangles

2 triangles (a×b/2) = 8×6/2 = 24 cm²

48 cm²

1 rectangle 6×12 = 72 cm²

72 cm²

1 rectangle 8×12 = 96 cm²

96 cm²

1 rectangle 10×12 = 120 cm²

120 cm²

total : 48+72+96+120 = 336 cm²

4. 6 rectangles

2 rectangles of 3×10 = 30 cm²

60 cm²

2 rectangles of 3×9 = 27 cm²

54 cm²

2 rectangles of 10×9 = 90 cm²

180 cm²

total : 60+54+180 = 294 cm²

step-by-step explanation:

they are simplified

step-by-step explanation: