Question

4th question help please

Answer 1

Hey there! :)

You have to find the area of all of them and add it together.

Formulas:

Area of a square: l · w
Area of a triangle: (b · h) ÷ 2

Square - 

l = 2
w = 2

2 × 2 = 4

Triangle - 

b = 2
h = 4

(4 · 2) ÷ 2
   8   ÷   2 = 4

There are 4 triangles

4 × 4 = 16

16 + 4 = 20

The surface area ⇒ 20 cm²

Answer 2

SA of a pyramid: 1/2ph + B
p = perimeter of base
h = slant height
B = area of base

Perimeter of base:
The pyramid has a square base, so take a side of the base and multiply it by 4 sides to find the perimeter of the base.
(2)(4) = 8 cm

Slant height: 
The diagram shows that the slant height of the pyramid is 4 cm.

Area of base:
Since the pyramid has a square base, square one side of the base to find the area of the pyramid.
2cm² = 4 cm²

Now plug in the perimeter, slant height, and area of the base into the formula for SA of a pyramid.

1/2(8)(4) + 4 
16 + 4 = 20 cm²

The surface area of the pyramid is 20 cm².