The bases of the trapezium are 6 inches and 2 inches, the sides are 0.13 m and 0.37 m. Find the area of the trapezoid.
To solve the problem, you first need to draw a perpendicular height from the smaller base of the trapezoid to the larger one.
In this case, we get two right-angled triangles.
Since we know the lateral sides of the trapezoid, which are the hypotenuses of the triangle, we find the height by the Pythagorean theorem, where:
A – the first leg
B – the second leg (in this case, the height of the trapezoid)
C – hypotenuse (side of the trapezoid)
In this case, we get:
B ^ 2 = C ^ 2 – A ^ 2.
Since the trapezoid is not equilateral, we will compose a system of equations in which we write the height as x, and the first leg as y.
We translate the value of quantities into one dimension:
0.13 m = 1.3 dm.
0.37 m = 3.7 dm.
We find the difference in bases.
6 – 2 = 4 dm.
In this case, we get:
x ^ 2 + y ^ 2 = 1.3 ^ 2
x ^ 2 + (4 – y) ^ 2 = 3.7 ^ 2
Let us express x through the first equation:
x ^ 2 = 1.3 ^ 2 – y ^ 2.
Substitute the x value in the second equation:
1.3 ^ 2 – y ^ 2 + (4 – y) ^ 2 = 3.7 ^ 2.
(4 – y) ^ 2 – y ^ 2 = 3.7 ^ 2 – 1.3 ^ 2.
-8 * y = -4.
y = 4/8 = 0.5 dm.
Find the height x.
x ^ 2 + 0.5 ^ 2 = 1.3 ^ 2.
x ^ 2 + 0.25 = 1.69.
x ^ 2 = 1.44.
x = 1.2 dm.
Determining the area of a trapezoid
To determine the area of the trapezoid, we use the following formula:
S = 1/2 * (M1 + M2) * H,
Where:
S is the area of the trapezoid;
M1 – smaller base;
M2 – larger base;
H is the height.
Substitute the known values and get:
S = 1/2 * (6 + 2) * 1.2.
S = 1/2 * 8 * 1.2 = 4 * 1.2 = 4.8 dm ^ 2.
Answer:
The area of the trapezoid is 4.8 dm ^ 2.