Name: JULY ROLAND P. CABRISOS Year & Section: 1ST YEAR – BSCE_1N_C14 Date: MAY 10, 2021 Score: Activity 3.2: Measurement of Solids Direction: Answer the following problem and show your complete solution. For some problems, leave your answers in terms of π . 1. Consider a regular pentagonal prism. Find the following: 360° π= π 360° π= 5 π = 72° π = 36° 2 4 tan 36° = π π = π. ππ , π = π , π = ππ i) Area of the base. 1 π΄πππ ππ π‘βπ πππ π = 2 × × 5 × π × π 2 π΄πππ ππ π‘βπ πππ π = 5 × 5.51 × π π¨πππ ππ πππ ππππ = πππ. π πππππ ii) Lateral surface area. πΏππ΄ = 5 × π × β πΏππ΄ = 5 × 8 × 20 π³πΊπ¨ = πππ πππππ iii) Total surface area. πππ΄ = 5ππ + 5πβ πππ΄ = 5(5.51)(8) + 5(8)(20) π»πΊπ¨ = ππππ. π πππππ iv) Volume of the solid. 5 ππππ’ππ = × π × β 2 5 ππππ’ππ = × 8 × 20 2 π½πππππ ππ πππ πππππ = πππ πππππ 2. Consider a regular hexagonal pyramid. Find the following: i) Area of the base. 3√3 2 π΄πππ ππ π‘βπ πππ π = π 2 3√3 2 π΄πππ ππ π‘βπ πππ π = 10 2 π¨πππ ππ πππ ππππ = πππ. ππ πππππ ii) Lateral surface area. 1 πΏππ΄ = 6 × × π × β 2 1 πΏππ΄ = 6 × × 10 × 22 2 π³πΊπ¨ = πππ πππππ iii) Total surface area. πππ΄ = π΄πππ ππ π‘βπ πππ π + πΏππ΄ πππ΄ = 259.81 + 660 π»πΊπ¨ = πππ. ππ πππππ iv) Volume of the solid. 10⁄ 2 π‘ππ30° = π 5 π= π‘ππ30° π = π√π β = √π 2 − π2 β = √222 − (5√3)2 π = ππ. ππ ππππ’ππ = π × π × β ππππ’ππ = 5√3 × 10 × 20.22 π½πππππ = ππππ. ππ πππππ 3. The solid to the right is a prism with a pyramid on its top. Find the following: i) Area of the base. π΄πππ ππ π‘βπ πππ π = π 2 π΄πππ ππ π‘βπ πππ π = 42 π¨πππ ππ πππ ππππ = ππ ππ.π ii) Lateral surface area of the prism. πΏππ΄ ππ π‘βπ ππππ π = β × πππππππ‘ππ πΏππ΄ ππ π‘βπ ππππ π = 5 × (4 + 4 + 4 + 4) π³πΊπ¨ ππ πππ πππππ = ππ ππ.π iii) Lateral surface area of the pyramid. Finding the slant height (x) π₯ = √62 + 42 π = π. ππ ππ. 1 × πππππππ‘ππππ πππ π × π ππππ‘ βπππβπ‘ (π₯) 2 1 πΏππ΄ ππ π‘βπ ππ¦πππππ = × (4 + 4 + 4 + 4) × 7.21 2 π³πΊπ¨ ππ πππ πππππππ = ππ. ππ ππ.π iv) Total surface area of the entire solid. πππ΄ ππ π‘βπ πππ‘πππ π ππππ = πΏππ΄ ππ ππππ π + πΏππ΄ ππ ππ¦πππππ πππ΄ ππ π‘βπ πππ‘πππ π ππππ = 80 + 57.68 π»πΊπ¨ ππ πππ ππππππ πππππ = πππ. ππ ππ.π v) Volume of the prism. ππππ’ππ ππ π‘βπ ππππ π = β × ππππ ππ πππ π ππππ’ππ ππ π‘βπ ππππ π = 5 × 16 π½πππππ ππ πππ πππππ = ππ ππ.π πΏππ΄ ππ π‘βπ ππ¦πππππ = vi) Volume of the pyramid. ππ€β ππππ’ππ ππ π‘βπ ππ¦πππππ = 3 4×4×6 ππππ’ππ ππ π‘βπ ππ¦πππππ = 3 π½πππππ ππ πππ πππππππ = ππ ππ.π vii) Volume of the entire solid. ππππ’ππ ππ π‘βπ πππ‘πππ π ππππ = π£πππ’ππ ππ ππππ π + π£πππ’ππ ππ ππ¦πππππ ππππ’ππ ππ π‘βπ πππ‘πππ π ππππ = 80 + 32 π½πππππ ππ πππ ππππππ πππππ = πππ ππ.π 4. The solid to the right is a cube with a cone cut out. Find the following: i) Area of the base of the cube. π΄πππ ππ π‘βπ πππ π = π2 π΄πππ ππ π‘βπ πππ π = 62 π¨πππ ππ πππ ππππ ππ πππ ππππ = ππ πππ ii) Lateral surface area of the cube. πΏππ΄ ππ π‘βπ ππ’ππ = 4π2 πΏππ΄ ππ π‘βπ ππ’ππ = 4 × 62 πΏππ΄ ππ π‘βπ ππ’ππ = πππ πππ iii) Area of the circle of the cone. π΄πππ ππ π‘βπ ππππππ ππ π‘βπ ππππ = ππ 2 π΄πππ ππ π‘βπ ππππππ ππ π‘βπ ππππ = π × 22 π¨πππ ππ πππ ππππππ ππ πππ ππππ = ππ πππ iv) Lateral surface area of the cone. πΏππ΄ ππ π‘βπ ππππ = ππ√π 2 + β2 πΏππ΄ ππ π‘βπ ππππ = π × 2√22 + 62 π³πΊπ¨ ππ πππ ππππ = ππ √ππ πππ v) Total surface area of the entire solid. πππ΄ ππ π‘βπ πππ‘πππ π ππππ = 6π2 πππ΄ ππ π‘βπ πππ‘πππ π ππππ = 6 × 62 π»πΊπ¨ ππ πππ ππππππ πππππ = πππ πππ vi) Volume of the cube. ππππ’ππ ππ π‘βπ ππ’ππ = π3 ππππ’ππ ππ π‘βπ ππ’ππ = 63 π½πππππ ππ πππ ππππ = πππ πππ vii) Volume of the cone. 1 ππππ’ππ ππ π‘βπ ππππ = ππ 2 β 3 1 ππππ’ππ ππ π‘βπ ππππ = π × 22 × 6 3 π½πππππ ππ πππ ππππ = ππ πππ viii) Volume of the entire solid. ππππ’ππ ππ π‘βπ πππ‘πππ π ππππ = ππππ’ππ ππ ππ’ππ + ππππ’ππ ππ ππππ ππππ’ππ ππ π‘βπ πππ‘πππ π ππππ = 216 + 8π π½πππππ ππ πππ ππππππ πππππ = πππ. ππ πππ 5. The solid to the right is a hemisphere with a cone on its top. Find the following: i) Area of the great circle (or the base of the cone). π΄πππ ππ π‘βπ πππππ‘ ππππππ = ππ 2 π΄πππ ππ π‘βπ πππππ‘ ππππππ = π × 392 π¨πππ ππ πππ πππππ ππππππ = πππππ ππ.π ii) Lateral surface area of the hemisphere. πΏππ΄ ππ π‘βπ βππππ πβπππ = 2ππ 2 πΏππ΄ ππ π‘βπ βππππ πβπππ = 2π × 392 π³πΊπ¨ ππ πππ ππππππππππ = πππππ ππ.π iii) Lateral surface area of the cone. πΏππ΄ ππ π‘βπ ππππ = ππ√β2 + π 2 πΏππ΄ ππ π‘βπ ππππ = π × 39√(81 − 39)2 + 392 π³πΊπ¨ ππ πππ ππππ = ππππ √πππ ππ.π iv) Total surface area of the entire solid. πππ΄ ππ π‘βπ πππ‘πππ π ππππ = πΏππ΄ ππ π‘βπ βππππ πβπππ + πΏππ΄ ππ π‘βπ ππππ πππ΄ ππ π‘βπ πππ‘πππ π ππππ = 3042π ππ‘.2 + 117π √365 ππ‘.2 π»πΊπ¨ ππ πππ ππππππ πππππ = πππππ. ππ ππ.π vi) Volume of the hemisphere. 2 ππππ’ππ ππ π‘βπ βππππ πβπππ = π × π 3 3 2 ππππ’ππ ππ π‘βπ βππππ πβπππ = π × (39)3 3 π½πππππ ππ πππ ππππππππππ = ππππππ ππ.π vii) Volume of the cone. β ππππ’ππ ππ π‘βπ ππππ = ππ 2 3 (81 − 39) 2 ππππ’ππ ππ π‘βπ ππππ = π(39) 3 π½πππππ ππ πππ ππππ = ππππππ ππ.π viii) Volume of the entire solid. ππππ’ππ ππ π‘βπ πππ‘πππ π ππππ = ππππ’ππ ππ βππππ πβπππ + ππππ’ππ ππ ππππ ππππ’ππ ππ π‘βπ πππ‘πππ π ππππ = 39546π ππ‘.3 + 21294π ππ‘.3 π½πππππ ππ πππ ππππππ πππππ = ππππππ ππ.π 7. Below are two similar square pyramids with a volume ratio of 8:27. The base lengths are equal to the heights. Use this to answer the following questions. i) What is the scale factor? Given that the ratio of their volume is 8: 27 which means that the ratio of their π π base lengths will be (π)π βΆ (ππ)π or 2 : 3 which is the scale factor. ii) What is the ratio of the total surface areas? The ratio of the total surface area will be ππ βΆ ππ ππ π βΆ π . iii) Find π, π, and π. As it is given that the base length is equal to height, it means that for smaller pyramid, y = 8 from the scale factor, we can say that 8 βΆ π₯=2βΆ3 8×3 π₯= 2 π₯ = 12 So, x = 12 and consequently, h = 12. iv) Find π and π. w is the hypotenuse of a right triangle whose perpendicular is 8 and base is half of 8 which is 4 So, π€ = √82 + 42 π = π√π Similarly, z is the hypotenuse of a right triangle whose perpendicular is 12 and base is half of 12 which is 6 So, π§ = √122 + 62 π = π√π v) What is volume of smaller pyramid? 1 × ππππ ππ πππ π × β 3 1 ππππ’ππ ππ π‘βπ π ππππππ ππ¦πππππ = × (8 × 8) × 8 3 πππ π½πππππ ππ πππ πππππππ πππππππ = πππππ π ππππ’ππ ππ π‘βπ π ππππππ ππ¦πππππ = vi) What is volume of larger pyramid? Using the scale factor, 512 βΆπ 3 27 × 512 π= 3×8 π½πππππ ππ πππ ππππππ πππππππ = πππ πππππ 8 βΆ 27 = v) Find the measure of one lateral surface area of smaller pyramid. 1 πΏππ΄ ππ π‘βπ π ππππππ ππ¦πππππ = × πππ π × βπππβπ‘ 2 1 πΏππ΄ ππ π‘βπ π ππππππ ππ¦πππππ = × 8 × 8 2 π³πΊπ¨ ππ πππ πππππππ πππππππ = ππ πππππ v) Find the measure of one lateral surface area of larger pyramid. Using the scale factor, 4 βΆ 9 = 32 βΆ π΄ 9 × 32 π΄= 4 π³πΊπ¨ ππ ππππππ πππππππ = ππ πππππ