Answer:
25% increase
Step-by-step explanation:
S+(2+1/2)s+20=48
2/2s+5/2s=48-20
7/2s=28
7s=28*2=2(20+8)=40+16
7s=56
s=56/7
s=8
if you notice the triangle on the left-hand-side, it has a base of 8 ft and a height/altitude of 10.
now, the triangular pyramid has 3 of those triangles standing up, and one at the base lying down, so 4 triangles with that base and altitude. So we can simply find the area of all 4 of those triangles, sum them up and that's the area of the triangular pyramid.
![\bf \stackrel{\textit{area of the four triangles}}{4\left[ \cfrac{1}{2}(8)(10) \right]}](https://tex.z-dn.net/?f=%20%5Cbf%20%5Cstackrel%7B%5Ctextit%7Barea%20of%20the%20four%20triangles%7D%7D%7B4%5Cleft%5B%20%5Ccfrac%7B1%7D%7B2%7D%288%29%2810%29%20%5Cright%5D%7D%20)
Answer:
9
Step-by-step explanation: