Question

Help me please find the surface area:

Answer 1

Step-by-step explanation:

this consists of 5 sides

top and bottom (equal)

left

right

front

the total surface area is the sum of all 5 areas.

the area of a rectangle is

length × width

the area of a triangle is

baseline × height / 2

in our case we have

top and bottom : 10×4/2 × 2 = 10×4 = 40 cm²

left : 8×9 = 72 cm²

right : 5×9 = 45 cm²

front : 10×9 = 90 cm²

the total surface area is

40 + 72 + 45 + 90 = 247 cm²