# A rectangle has dimensions of 3a by 5b. How do you write simplified expressions for the area and perimeter of this rectangle?

Jul 1, 2016

$a r e a = 15 a b$ and $P e r i m e t e r = 6 a + 10 b$

#### Explanation:

Write expressions for the area and perimeter using the variables, in exactly the same way as with numbers. However, it is not possible to get a final numerical answer.

$A r e a = l \times b \text{ } A r e a = 3 a \times 5 b = 15 a b$

Perimeter is the sum of all the sides of a shape.

$P e r i m e t e r = l + b + l + b$

$P = 3 a + 5 b + 3 a + 5 b = 6 a + 10 b$