Answer: perimeter = 96mm, Area = 564mm².
Explanation:
From the diagram, it is a trapezium, it has a rectangle joined together by a right angled triangle. Now to find the perimeter, we add all the dimensions together. To get the other side of the rectangle, which is also the perpendicular height of the figure, we take the Pythagoras. Let the perpendicular height = x
Therefore,
25² = ײ + 7²
625 = x² + 49
x² = 625 - 49
x² = 576
x. = √576
= 24.
Now the perimeter
= 20 + 25 + 7 + 20 + 24
= 96mm.
Area of the figure will be
= 1/2( a + b )h
Where a = 20, b = 20 + 7 = 27 and h = 24, now substitute for the values
( 20 + 27) x 24
---------------------
2
= 47 x 24/2
= 47 x 12
= 564mm²