Answer: The equation you will use would be 40x + 15x =115. you're welcome.
Answer:

Step-by-step explanation:
Notice that all three sides of the given triangle has one tick mark.
This means that all three sides are congruent, meaning that we have an equilateral triangle.
And for equilateral triangles, all three angles are also congruent.
So:

Also, recall that the interior angles of a triangle is always 180. Thus:

Substitute:

Combine like terms:

Substitute:

Multiply:

Thus:

And we are done!
Do you have a picture to show, so that I can help?
Answer:
225 cm ^ 3
Step-by-step explanation:
First find the volume of the rectangle that is most horizontal.
L * W * H = 10 * 3 * 3 = 90
Then find the volume of the most vertical rectangle
L * W * H = 15 * 3 * 3 = 135
add them together to get...
225