Question

Given: ABCD is a trapezoid, AD = 10, BC = 8, Area of ∆ACD = 30. Find: Area of ABCD

Answer 1

Just multiply them.
10 times 8 equals 80.
Area=80

Answer 2

`\text{The area of trapezoid ABCD is }54 units^2`

Explanation:

Given that ABCD is a trapezoid, AD = 10, BC = 8 and the area of ∆ACD = 30.

we have to find the area of trapezoid ABCD.

`\text{Area of triangle ACD}=(1)/(2)* base* height`

`30=(1)/(2)* 10* h`

`h=(30* 2)/(10)=6 units`

The area of trapezoid can be calculated by the formula

`=(1)/(2)* (\text{sum of parallel sides})* height`

`=(1)/(2)* (AD+BC)* h`

`=(1)/(2)* (10+8)* 6`

`=(1)/(2)* 18* 6=54 units^2`

`\text{Hence, the area of trapezoid ABCD is }54 units^2`