Answer:
![\mathbf{surface \ area} = \mathbf {64.5 cm^2}](https://img.qammunity.org/2021/formulas/chemistry/middle-school/d6970bwugitcz738a3mgssm2o7m5pb4uxc.png)
Step-by-step explanation:
The missing diagram is attached in the file below:
The formula for calculating the surface of triangular prism is expressed as:
![\mathbf{surface \ area} = \mathbf {bh + (s_1 + s_2 + s_3)H}](https://img.qammunity.org/2021/formulas/chemistry/middle-school/qcb0iq0q0qt8dtauxc1n5yx16y82q5k0p4.png)
where ;
base b = 28 mm = 2.8 cm
height h of the triangle = 3.75 cm
the sides of the triangle
= 2.8 , 4 and 4 respectively
the height if the prism H = 5 cm
![\mathbf{surface \ area} = \mathbf {(2.8*3.75)+ (0.28 + 4+ 4)5}](https://img.qammunity.org/2021/formulas/chemistry/middle-school/klgaw8jyb50os6g0e3inau2d99zovwq82e.png)
![\mathbf{surface \ area} = \mathbf {(10.5)+ (8.28)5}](https://img.qammunity.org/2021/formulas/chemistry/middle-school/t6k92gibonpm5310iixqe2z0e4kuv4pr1f.png)
![\mathbf{surface \ area} = \mathbf {(10.5)+ (54)}](https://img.qammunity.org/2021/formulas/chemistry/middle-school/85ai0stuta513xehq5dodn85ja51d7hzst.png)
![\mathbf{surface \ area} = \mathbf {64.5 cm^2}](https://img.qammunity.org/2021/formulas/chemistry/middle-school/d6970bwugitcz738a3mgssm2o7m5pb4uxc.png)