what am i doing wrong? i cannot figure out why i can't get the surface area. the answer says it's 69.3cm^3. please help me

Step-by-step explanation:

First, let's calculate surface area of cuboid first:

L = 4.8 cm

B = 1.5 cm

H = 2.1 cm

Surface Area of Cuboid = 2 x (LB + BH + LH)

                                        = 2 x (4.8x1.5 + 1.5x2.1 + 4.8x2.1)

                                        = 2 x ( 7.2 + 3.6 + 10.08)

                                        = 41.76 cm2

Surface Area of Triangular prism = Area of Front and Back triangle + Area of Side triangles + Area of the bottom rectangle

Area of front and back triangles = 2 x (1/2)x 4.8 x 5.5 = 26.4 cm2

Area of side triangles = 2 x (1/2) x 1.5 x 5.5 = 8.25 cm2

Area of botton rectangle = 4.8 x 1.5 = 7.2 cm2

Now to get the area of the whole shape = Surface Area of Cuboid + Surface Area of Triangular prism - Area of the bottom rectangle

Note: In order to get the surface area of the given shape, the bottom of the prism or the top of the cuboid needs to be subtracted.

Area = 41.76 + (26.4+8.25) - 7.2

Area = 69.21 cm2

step-by-step explanation: