Calculate Trapezoid Height: Finding AE Given Area 45 cm² and Bases 4 cm, 6 cm

Question

The area of trapezoid ABCD is equal to 45 cm².

The base of the trapezoid BC is equal to 4 cm.

The base of the trapezoid AD is equal to 6 cm.

Calculate the length of AE.

S=45S=45S=45444666AAABBBCCCDDDEEE

Video Solution

Solution Steps

00:13 Let's find the height AE.
00:16 We'll use the trapezoid area formula.
00:19 Add the bases, multiply by the height, and then divide by two.
00:28 Now, substitute the values from the data and solve for the height.
00:58 Let's isolate height AE to find its value.
01:11 And that's how we solve the question!

Step-by-Step Solution

The problem can be solved using the formula for the area of a trapezoid:

S=12×(b1+b2)×h S = \frac{1}{2} \times (b_1 + b_2) \times h

Where b1 b_1 and b2 b_2 are the lengths of the two parallel sides (bases) of the trapezoid, and h h is the height. For this trapezoid, the data given is:

  • Area, S=45cm2 S = 45 \, \text{cm}^2
  • Base 1, b1=4cm b_1 = 4 \, \text{cm}
  • Base 2, b2=6cm b_2 = 6 \, \text{cm}

Substitute these values into the area formula:

45=12×(4+6)×h 45 = \frac{1}{2} \times (4 + 6) \times h

Simplify the formula:

45=5×h 45 = 5 \times h

Divide both sides of the equation by 5 to solve for h h :

h=455=9 h = \frac{45}{5} = 9

Thus, the length of AE, or the height of the trapezoid, is 9cm \mathbf{9 \, \text{cm}} .

Therefore, the solution to the problem is that the length of AE is 9cm 9 \, \text{cm} .

Answer

9