A.) the perimeter is cm.
b.) the area is square cm.

a) Perimeter  = 10.25 cm

b) Area = 5 cm²

Step-by-step explanation:

a) Perimeter

To find the perimeter we need to add the measure of the three sides of the triangle

P = 2.75 cm + 3.5 cm + 4 cm = 10.25 cm

b) Area

To find the area we need the length of the height and the length of the base.

base = 4 cm

height = 2.5 cm

Formula

Area = base x height /2

Area = 4 x 2.5 / 2 = 5 cm²

4 and 5)16.97 or 12√2

6)15.59 or 9√3

7)y = 15.59 or 9√3     x =27

8)17.80