Question:
ABCD is a trapezium in which AB ∥ CD, AD ⊥ DC, AB = 4 cm, BP = 7 cm and DC = 25 cm, then area of the trapezium is ____.
Answer:
101.5cm²
Explanation:
The figure for the trapezium ABCD is attached to this response.
To find the area of the trapezium, we use the formula for calculating the area of a trapezium given as follows;
A =
x (a + b) x h ------------------(i)
Where;
A = area of the trapezium
a and b are the parallel sides of the trapezium
h = height of the trapezium.
As shown in the figure,
AB and CD are parallel
Therefore, we can say that;
a = AB
b = CD
Also, from the figure,
The height of the trapezium is BP
Therefore, we can say that;
h = BP
We know that;
a = AB = 4cm
b = CD = 25cm
h = BP = 7cm
Substitute these values of a, b and h into equation (i) as follows;
A =
x (4 + 25) x 7
A =
x (29) x 7
A = 101.5
Therefore, the area of the trapezium is 101.5cm²