Parallelogram Side Length: Finding AB When 3X=6 and Perimeter=40cm

To solve this problem, let's follow these steps:

• Step 1: Calculate the length of $CD$ using the given $X = 2$.
• Step 2: Use the perimeter formula for the parallelogram to find $AB$.
• Step 3: Solve for the unknown length $AB$.

Step 1: Calculate the length of $CD$.

Given $X = 2$, we find $CD = 3X = 3 \times 2 = 6$ cm.

Step 2: Use the formula for the perimeter of a parallelogram:
$P = 2 \times (AB + CD)$.

Substitute the given values:
$40 = 2 \times (AB + 6)$.

Step 3: Solve for $AB$.

Start by dividing the entire equation by 2:
$20 = AB + 6$.

Subtract 6 from both sides to isolate $AB$:
$AB = 20 - 6 = 14$.

Therefore, the length of side $AB$ is $14$ cm.