Im confusion? Could someone help me out.

20cm

Step-by-step explanation:

for the triangle:

Perimeter = 30cm

a + a + a = 30

3a = 30

hence a = 10cm

For the rectangle:

Perimeter = 30cm

a + a + b + b = 30

but a = 10cm

10 + 10 + b + b = 30

20 + 2b = 30

2b = 10

hence b = 5cm

Perimeter of square = b + b + b + b

= 5 + 5 + 5 + 5 = 20cm

for b its (t) and c its (d)

step-by-step explanation:

rick has $1400 and sally has $1500

step-by-step explanation:

to find amount of money rick has after 10 years :

principal = $1000 , time = 10 years , rate = 4% annually

to find amount of money sally has after 10 years :

her friend gives to pay her $50 per year, therefore money she has after 10 years = 50 × 10 = $500

also, sally gets $1000 after 10 years,

therefore, total amount of money sally has after 10 years = 500 + 1000 = $1500

so, after 10 years : rick has $1400 and sally has $1500