The picture won't load, but I would surely help!
Answer: The carpenter will need 84 square inches of wood.
In this problem we are looking for the surface area of the jewelry box. This box has 5 faces. The two triangles at each end and the 3 rectangle pieces between them.
The sides of the triangles are 3, 4, 5 which always forms a right triangle with legs of 3 and 4. Use the formula for the area of a triangle, we have 3 x 4 / 2 = 6. The area of each triangle is 6 square inches.
Now, the three sides, each one has a height of 6.
3 x 6 = 18
4 x 6 = 24
5 x 6 = 30
If we add all the sides together, we get an area of 84 square inches.
6 + 6 + 18 + 24 + 30 = 84
Yes for the first one, yes for the second one, and yes for the third one although your subtraction equation had the wrong year (its not 1847 its 1846) but the answer was right, 65.