Constructing the House Roof

Scene 1 — Understanding the House Visual / animation: Visuals: Show the textbook-style house construction. Label base DE = 5 cm, side BD = 5 cm, side CE = 5 cm, door width = 1 cm, and door height = 2 cm. Voice-over: “We are going to construct a house using geometric tools. The base and both side walls are five centimetres long. We now need to construct the roof accurately.” Scene 2 — Finding the Roof Point Visual / animation: Visuals: Highlight B and C at the tops of the walls. Show the missing roof point A above them. Voice-over: “Let the missing roof point be A. The distance AB must be five centimetres, and the distance AC must also be five centimetres. Therefore, point A must be five centimetres away from both B and C.” On screen: AB = AC = 5 cm. Scene 3 — Drawing the First Arc Visual / animation: Visuals: Show the compass being set to 5 cm using a ruler. Keep its opening fixed. Place the compass point at B and draw an arc. Voice-over: “First, set the compass to a radius of five centimetres. With B as the centre, draw an arc. Every point on this arc is five centimetres away from B.” On screen: Centre B | Radius 5 cm. Scene 4 — Drawing the Second Arc Visual / animation: Visuals: Without changing the compass opening, place the compass point at C and draw a second arc. Highlight the upper intersection. Voice-over: “Next, keep the same compass opening. With C as the centre, draw another arc. The arcs intersect at point A. This point is five centimetres from B and five centimetres from C.” Label the intersection A. Scene 5 — Completing the Roof Visual / animation: Visuals: Join A to B and A to C with straight lines. Then use A as the centre and a 5 cm radius to draw the curved roof from B to C, matching the textbook illustration. Voice-over: “Join A to B and A to C. Now, with A as the centre and a radius of five centimetres, draw the roof curve connecting B and C. The house construction is complete.” Scene 6 — Recall and Challenge Visual / animation: Visuals: Show the completed house. Briefly highlight the equal-radius arcs, then display the 7 cm challenge. Voice-over: “Remember, equal-radius arcs from two given points help us locate a point at the required distance from both. Now try constructing a bigger house in which every outer boundary side is seven centimetres long.” On screen: Your Challenge — Construct the 7 cm House.