1. **State the problem:** Determine the surface area of the birdhouse with a rectangular base of dimensions 26 cm by 25 cm, a height of 18 cm, and a triangular roof with slant height 18 cm. 2. **Identify the parts of the birdhouse:** - Base: rectangle 26 cm by 25 cm - Walls: 4 rectangular sides, two with height 18 cm and length 26 cm, two with height 18 cm and length 25 cm - Roof: two triangular faces with slant height 18 cm - Front pentagon with a circular hole (we will subtract the hole area) 3. **Calculate the base area:** $$\text{Base area} = 26 \times 25 = 650 \text{ cm}^2$$ 4. **Calculate the wall areas:** - Two walls of size $26 \times 18$: $$2 \times (26 \times 18) = 2 \times 468 = 936 \text{ cm}^2$$ - Two walls of size $25 \times 18$: $$2 \times (25 \times 18) = 2 \times 450 = 900 \text{ cm}^2$$ - Total wall area: $$936 + 900 = 1836 \text{ cm}^2$$ 5. **Calculate the roof area:** - Each triangular face has base 26 cm and slant height 18 cm. - Area of one triangle: $$\frac{1}{2} \times 26 \times 18 = 234 \text{ cm}^2$$ - Two triangles: $$2 \times 234 = 468 \text{ cm}^2$$ 6. **Calculate the front pentagon area and subtract the circular hole:** - Since exact pentagon dimensions are not given, assume the front wall area is included in the walls calculation. - The circular hole area (assuming radius $r$ is not given) cannot be subtracted without radius, so we omit it. 7. **Sum all areas for total surface area:** $$650 + 1836 + 468 = 2954 \text{ cm}^2$$ **Final answer:** The approximate surface area of the birdhouse is **2954 cm\textsuperscript{2}**.