Answer:

Step-by-step explanation:
(Look at the picture).
Calculate the area of the rectangle and subtract the areas of red triangles.
The formula of an area of a rectangle:

We have:

substitute:

The formula of an area of a triangle:

substitute:

Area of ΔRST:

substitute:

Answer:
117
Step-by-step explanation:
Given
72 ÷ 8 + 4y³ with y = 3, substitute y = 3 into the expression
= 72 ÷ 8 + 4 × 3³ ← evaluate exponent
= 72 ÷ 8 + 4 × 27 ← evaluate division and multiplication
= 9 + 108 ← calculate addition
= 117
Given mass=1 kg, volume=400cm³, density=?
The formula for finding density is ρ=m/v where ρ is density, m is volume and vis volume
ρ=1kg/400cm³
ρ=0.0025kg/cm³
Therefore the density of the sand is 0.0025kg/cm³
1) perimeter = 36 ft
explanation:
p=2l+2w
p=2(8)+2(10)
p=16+20
p=36
area = 80 ft^2
explanation
a=l*w
a=8 ft* 10 ft
a=80 ft^2
2) perimeter = 28
explanation:
p=2l+2w
p=2(7)+2(7)
p=14+14
p=28
area = 49 in^2
explanation:
a=l*w
a=7in*7in
a=49 in^2