Understand the geometry and set up a coordinate system.

Step 1: Understand the geometry and set up a coordinate system.
The figure shows a roof structure ABCDEF.

• ABCD is the rectangular base.
• AB = 10 cm.
• EF is the ridge, centrally placed, and EF = 6 cm. This implies EF is parallel to AB and CD.
• FC = 8 cm.
• The right angle symbol at E indicates that the line from E perpendicular to AD (let's call the foot of the perpendicular M) forms a right angle. This means the plane ADEF is perpendicular to the base ABCD along AD, or more likely, the height of E above AD is perpendicular to AD. Given "centrally placed", it means the roof is symmetric.

Let's place the