let width = x – 13

x + x – 13 = 51 since 51 is half of the perimeter.

2x – 13 = 51 combine like terms

2x = 64 at 13 to both sides

x = 32 divide both sides by 2

Therefore your length equals 32cm and the width equals 19cm.

A = lw

A = 32(19)

A = 608 sq. cm

2) let x = each equal side of isosceles triangle

let 0.5x – 1 = the base

x + x + (0.5x – 1) = 48

2.5x – 1 = 48 combine like terms

2.5x = 49 add 1 to both sides

x = 19.6 divide both sides by 2.5

Each equal side of the isosceles triangle measures 19.6in and the base equals 8.8in.

(the length) + (the width)= 51 cm

(the length) – (the width) = 13 → (the length) = 13 + 13 + (the width) → [13 + (the width)+ (the width)]=51 →

2(the wide)=51-13 → the wide = 19

The length = 51 – ( the wide) → the length = 51- 19= 32

P=51*2=102cm

P= 2( l+b)

l-w=13

l=13+w

Substitue 13+w for l

102= 2((13+w)+w)

Solve the equation for w then whatever value you get for w subtitute it in l=13+w to find l

2)

P=48

Length of base: (1-1/2x)

48= (x)+(x)+(1-1/2x)

Solve the equation for x (2 sides of the triangle) then for the 3rd side use this 1-1/2x