Question

What is the surface area of the composite figure?

176 mm2
192 mm2
208 mm2
304 mm2

Answer 1

You have 4 triangles with Height = 3mm and base = 8 mm
and 5 rectangles with base= 8mm and height=2mm

Do you know the area of a triangle with respect to base and height?
ditto with rectangles?

Answer 2

Sorry 4 rectangles

Answer 3

Sorry but i still could not get this, how to solve ?

Answer 4

@ghazi can you able to help me with it?

Answer 5

its easy you can do it, it is sum of surface areas

Answer 6

Triangle area is 0.5 B H
so (3)(8) = 24 mm squared but there are 4 so (24)(4) mm squared for the roof.
For rectangles area is BH so (8)(2) = 16 but we have 4 so (16)(4)
the total surface area would be then the sum from the roof and the sides
or (24)(4) + (16)(4) = (38)(4) = 152 mm squared

Answer 7

Thank you so much guys :)

Answer 8

it's 4*(8*2)+(8*8)+4(2*1/2*4*3)

Answer 9

Thanks alot guys! :)

Answer 10

forgot the halves in the triangle calculation.
Triangle area is 0.5 B H
so 0.5(3)(8) = 12 mm squared but there are 4 so (12)(4) mm squared for the roof.
For rectangles area is BH so (8)(2) = 16 but we have 4 so (16)(4)
the total surface area would be then the sum from the roof and the sides
or (12)(4) + (16)(4) = (28)(4) = 112 mm squared
plus 64 for the bottom to get 176 mm squared

Answer 11

:) thanks @freewilly922 and @ghazi !! you guys are truly very awesome!!!!!!

Answer 12

you're welcome