(a) We know that,

Perimeter of a polygon = Sum of the lengths of all sides of that polygon

In this question, we have:

Perimeter = (4 + 2 + 1 + 5) cm = 12 cm

Hence, perimeter is 12 cm

(b) We know that,

Perimeter of a polygon = Sum of the lengths of all sides of that polygon

In this question, we have:

Perimeter = (23 + 35 + 40 + 35) cm

= 133 cm

(c) We know that,

Perimeter of a polygon = Sum of the lengths of all sides of that polygon

In this question, we have:

Perimeter = (15 + 15 + 15 + 15) cm

= 60 cm

(d) We know that,

Perimeter of a polygon = Sum of the lengths of all sides of that polygon

In this question, we have:

Perimeter = (4 + 4 + 4 + 4 + 4) cm

= 20 cm

(e) We know that,

Perimeter of a polygon = Sum of the lengths of all sides of that polygon

In this question, we have:

Perimeter = (1 + 4 + 0.5 + 2.5 + 2.5 + 0.5 + 4) cm

= 15 cm

(f) We know that,

Perimeter of a polygon = Sum of the lengths of all sides of that polygon

In this question, we have:

Perimeter = (1 + 3 + 2 + 3 + 4 + 1 + 3 + 2 + 3 + 4 + 1 + 3 + 2 + 3 + 4 + 1 + 3 + 2 + 3 + 4) cm

= 52 cm