Question

What are the surface areas of those ?

Answer 1

Answer:

7) $SA=13.8 yd^{2}$. 8)$SA=96yd^{2}$

Step-by-step explanation:

7)

Here we have two different types of faces.Bottom face and side faces which are equivalent.

To calculate the area of a trinagle we have the formula of area to be

$A=\frac{1}{2}ab$

where a is the height of the triangle and b is the base of the triangle.

here let us first calculate the area of the bottom face,

$a1=\frac{1}{2}*2.6*3$

$a1=3.9yd^{2}$

now for the top faces which are similar, areas would be

$a2=\frac{1}{2}*2.2*3$

$3*a2=9.9yd^{2}$

Hence the total area is

$9.9+3.9=13.8 yd^{2}$

8)

As we have seen in the above question area for a traingle would be

$A=\frac{1}{2}ah$ and for rectangle would be $lb$ where l and b are the lengths and breaths of the rectangle.

Area of traingles would be ,

$A1=\frac{1}{2}*3*4+ \frac{1}{2}*3*4$

$A1=12$

Area of rectangles would be,

$A2=7*4+7*5+7*3$

$A2=84$

Hence the total area is

$A=96$