On finding a perimeter and area and there is a decimal for the shape but the 2 other numbers on the shape don't. Do I multiply/add with the decimal on all numbers or only on that 1 number?

Question

EXAMPLE
There is a triangle
one side is 1.5
the base is 2
and the other side is 3

What do I do?

Answer 1

You can't ignore 0.5 of the unit.

Perimeter = 1.5 + 2 + 3 = 6.5

Answer 2

Same thing on area?

1.5 X 2.0 X 3.0=9000?

Answer 3

The area of a triangle is 1/2bh

What is the height?

If the height has a decimal, it must be used.

Answer 4

9.000?