Trapezoid Area Problem: Express Area with Height 2X and Parallel Sides (X+14) and (3X+7)

Question

Express the area of the trapezoid by X

X+14X+14X+143X+73X+73X+72X2X2X

Video Solution

Solution Steps

00:00 Express the area of the trapezoid using X
00:03 We'll use the formula for calculating trapezoid area
00:06 (Sum of bases(AB+DC) multiplied by height(H)) divided by 2
00:16 We'll substitute appropriate values according to the given data and solve for the area
00:31 We'll simplify what we can
00:37 We'll group the numbers as one factor and X as another factor
00:41 We'll properly distribute - multiply each factor by X
00:47 And this is the solution to the question

Step-by-Step Solution

To express the area of the trapezoid in terms of X X , follow these steps:

  • Step 1: Identify the given values for the trapezoid's dimensions. The top base b1 b_1 is X+14 X + 14 , the bottom base b2 b_2 is 3X+7 3X + 7 , and the height h h is 2X 2X .
  • Step 2: Use the trapezoid area formula A=12×(b1+b2)×h A = \frac{1}{2} \times (b_1 + b_2) \times h .
  • Step 3: Compute the sum of the bases: (X+14)+(3X+7)=X+14+3X+7=4X+21(X + 14) + (3X + 7) = X + 14 + 3X + 7 = 4X + 21.
  • Step 4: Calculate the area using the formula: A=12×(4X+21)×(2X) A = \frac{1}{2} \times (4X + 21) \times (2X) .
  • Step 5: Simplify: A=12×(4X+21)×2X=(4X+21)×X A = \frac{1}{2} \times (4X + 21) \times 2X = (4X + 21) \times X .
  • Step 6: Simplify further by distributing: A=4X2+21X A = 4X^2 + 21X .

Thus, the area of the trapezoid expressed in terms of X X is 4X2+21X 4X^2 + 21X .

Answer

4x2+21x 4x^2+21x