Question

I need help with this I don’t really understand this area and perimeter problems

Answer 1

Given: A trapezium with parlalle sides 15cm and 10cm. One non parallel side is 7cm and altitude is 6cm.

Required: The area and perimeter of trapezium.

Explanation:

Area of trapezium is

`A=(1)/(2)(Sum\text{ of parallel sides})(altitude)`

So here, parallel sides are 10 cm and 15 cm and altitude is 6 cm.

So area of trapezium is

`\begin{gathered} A=(1)/(2)(10+15)(6) \\ A=(1)/(2)(25)(6) \end{gathered}`

So

`\begin{gathered} A=25*3 \\ =75 \end{gathered}`

So area is 75 sq cm.

Now, perimeter is sum of all sides. The three sides are 15cm 10cm and 7cm. We need to find the fourth side to find the perimeter.

Fourth side is 7cm here by similarity.

So perimeter is

`\begin{gathered} P=15+10+7+7 \\ =39 \end{gathered}`

So perimeter is 39cm

Final Answer: The area is 75 sq cm and perimeter is 39 cm