Question

Find the total surface area of this prism where the cross-section is an isosceles triangle.

Perpendicular Height: 5cm
Base Length: 24cm
Base Side Length: 10cm

Answer 1

620cm squared

Explanation:

a=bxh/2

so this means

24x5/2=area of one triangle(60cm squared)

since there are two .that means the area for both triangles is 120cm squared

for the recatngles:

a=lxw

Substitute

10 × 13 = 130

since there are 2 of them,

130 × 2 = 260 cm^2

the rectangle on the bottom:

a=lxw

24x10=240cm squared

240+260+120=620

Answer 2

Explanation:

620 cm^2

Explanation:

Area of isosceles triangles:

A = (b×h) ÷ 2

Substitute

(24 × 5) ÷ 2

120 ÷ 2 = 60 cm^2

There are 2 triangles so:

60 × 2 = 120 cm^2

Area of 2 identical rectangles:

- They are identical and this is shown by the two short lines which indicate that this is an isosceles triangle. They have 2 identical sides.

A = L × W

Substitute

10 × 13 = 130

Because there are two:

130 × 2 = 260 cm^2

Area of the rectangle at the bottom:

- Let's not forget the rectangle at the bottom of this shape.

A = L × W

Substitute

24 × 10 = 240 cm^2

Add these all together to get the total surface area:

120 + 260 + 240 = 620 cm^2

Answer: 620 cm^2