## 123F What is the volume of this composite solid? A)588in3 B)784in3 C)915in3 D)980in3 2 years ago 2 years ago

1. 123F

2. dpflan

looks like this is made up of 3 objects: 2 cubes and a triangular prism

3. 123F

yes

4. dpflan

you have all the dimensions, so you just need to find the volume of each object and sum them

5. 123F

yes

6. 123F

but how?

7. dpflan

volume is $length * width * height$

8. dpflan

for instance, with the first rectangular prism on the left, 8in by 7in by 7in

9. 123F

cool

10. 123F

triangular prism?

11. dpflan

volume is the product of those 3 values, and the same for the other rectangular prism, now with the triangular prism just remember that $A=\frac{1}{2}*base*height$

12. dpflan

so you then multiply A by the 3rd dimension

13. 123F

so, length∗width∗height A=1\2∗base∗height

14. dpflan

and because you are multiplying values with "inches" as the units, the volume is in inches cubed, $in^3$

15. 123F

thank you

16. dpflan

17. Moderator

hey moderator my computer say its forbidden to get on here why is that

18. 123F

what do i use for the triangular prism?

19. 123F

dpfan

20. dpflan

yes?

21. dpflan

looking at the picture, it looks as though the length of the left side the triangle is equal to 8 and the length of the other side is equal to 7....

22. 123F

7*7*8 = 392 7*7*8 = 392 8*7/2=28 so 392+392+28=812in3