The perimeter of a trapezium is 52 cm and its each non-parallel side is equal to 10 cm with its height 8 cm. Its area is (in sq cm)
124
118
128
112
Answers
Answer:
Using Pythagoras' theorem, substitute in the values of the non-parallel side and the altitude:
10² = 8² - x²
x² = 36
x = 6
Therefore the base of the right-angled triangles is 6cm.
If we let the shorter parallel side of the trapezium = x, the longer parallel side will = x + 12.
P = x + x + 12 + 10 + 10 = 52
2x = 20
x = 10
Therefore the side lengths of the trapezium are 10, 10, 10 and 22.
A = h/2(a + b)
= 8/2 x 32
= 4 x 32
= 128cm²
Step-by-step explanation:
Answer :
The area of trapezium is 128 cm². [ Option c. 128cm² ]
Step-by-step explanation :
To Find,
- The area of trapezium is [ sq cm ]
Solution,
Given that,
- Perimeter of trapezium = 52cm
- The non-parallel sides of trapezium = 10cm
- Height ( distance between them ) = 8cm
To get the area of trapezium, first we need to find out the sum of parallel sides of trapezium.
A . T . Q
Let us assume the parallel sides of trapezium as x and y.
As we know that,
Perimeter of trapezium = a + b + c + d
Where,
- a, b, c and d are the sides of trapezium
∴ x + y + 10 + 10 = 52
➠ x + y + 10 + 10 = 52
➠ x + y + 20 = 52
➠ x + y = 52 - 20
➠ x + y = 32
The sum of the two parallel sides of trapezium are 32cm.
Now, we can find out the area of trapezium,
As we know that,
Area of trapezium = 1/2 × ( sum of parallel sides ) × Height
➠ 1/2 × 32 × 8 ...... dividing 8 and 2 with 2
➠ 32 × 4
➠ 128 ★
∴ The area of trapezium is 128 cm².