Question

Please help me! Need answer quick!

Answer 1

Let h = height of triangle

h^2 + 12^2 = 15^2

h^2 + 144 = 225

h^2 = 225 - 144

h^2 = 81

sqrt{h^2} = sqrt{81}

h = 9 cm

For part B, we need to find surface area because it represents the perimeter of this 3-D figure. The formula needed is SA = B + LA.

1. First find the lateral area.

LA = perimeter of triangle • height

LA = ph

p = 15 + 15 + 24

p = 30 + 24

p = 54 cm

LA = (54)(9)

LA = 486 cm^2

2. We now find the base of each triangle. This is found by finding the area of each triangle and multiplying by 2.

A = (1/2)bh

A = (1/2)(24)(9)

A = 108 cm^2

A = 2•108 cm^2

A = 216 cm^2 = our B in the surface area formula.

SA = B + LA

SA = 216 cm^2 + 486 cm^2

SA = 702 cm^2

The amount of cardboard needed is 702 cm^2.