Calculate Areas: Parallelograms with DC=10 and Height Constraint

Question

ABCD and DCFE are forllel

It is known that:

DC=10 AE=8

Angle BAE equals 90 degrees

The height of the forllelogram ABCD for DC is less band 80% of the size of the side DC

Calculates the sum of the areas of the forllelograms.

00:00 Calculate the sum of parallelogram areas

00:03 Opposite sides are parallel in parallelograms

00:09 Transitive property

00:18 Alternate angles sum to 180

00:25 Therefore this angle is also right

00:33 Opposite sides are equal in parallelograms

00:49 To find parallelogram area multiply height(H) by side(DC)

00:52 For each parallelogram multiply by its corresponding height (1,2)

01:00 Extract common factor

01:06 Sum of heights is the height itself (AE)

01:09 We'll substitute AE value and solve to find the areas

01:12 And this is the solution to the question

80 cm²