Answer:
Options 1, 3 and 4 are true
Step-by-step explanation:
The legs EF and DF of the right triangle DEF have lengths of 24 units and 7 units, respectively. By the Pythagorean theorem,
Find trigonometric functions:
Thus, options 1, 3 and 4 are true
Answer:
The lateral area of the figure = 480 m²
The surface area = 720 m²
Step-by-step explanation:
By definition, we have;
The lateral area is the area of the vertically facing sides of or the area of the triangular faces of a pyramid
The surface area is the area of the entire surface = Lateral area + The other surface areas of the object
For a pyramid, the surface area = Lateral area + Area of base
The figure in the question is a pentagon based pyramid with five triangles on the sides
The lateral area of the figure = 5 × area of the 5 triangles = 5 × Base × Height
The lateral area of the figure = 5 × 12 × 8 = 480 m²
The lateral area of the figure = 480 m²
The surface area = Area of the base + Lateral surface area
Area of the regular pentagon base = 1/2 × Perimeter of the pentagon × Apothem
Perimeter of the pentagon = 5 × 12 = 60 m
Apothem = Perpendicular distance from the pentagon's side to the center = 8.3 m
∴ Area of the regular pentagon base = 1/2 × 60 × 8 = 240 m²
∴ The surface area = 240 +480 =720 m²
The surface area = 720 m²
