The lengths of the parallel sides of a trapezium are 9cm and 12cm. If the area of the trapezium is 105cm\(^{2}\), find the perpendicular distance between th...
Assessment:WAEC SSCE - General Mathematics - 2022Subject:General Mathematics
The lengths of the parallel sides of a trapezium are 9cm and 12cm. If the area of the trapezium is 105cm\(^{2}\), find the perpendicular distance between the parallel sides.
Answer Details
To find the perpendicular distance between the parallel sides of a trapezium, we can use the formula for the area of a trapezium.
The formula for the area of a trapezium is given by:
Area = (1/2) * (sum of parallel sides) * (perpendicular distance between the parallel sides)
In this case, we are given:
Length of one parallel side = 9 cm
Length of the other parallel side = 12 cm
Area of the trapezium = 105 cm²
Let's denote the perpendicular distance between the parallel sides as "h."
Using the formula for the area of a trapezium, we can rewrite it as:
105 = (1/2) * (9 + 12) * h
Simplifying the equation:
105 = (1/2) * 21 * h
Multiplying both sides by 2 to eliminate the fraction:
210 = 21h
Dividing both sides by 21 to solve for "h":
h = 210 / 21
h = 10 cm
Therefore, the perpendicular distance between the parallel sides of the trapezium is 10 cm.
So, the correct answer is 10 cm.