What is the total surface area

Question

asked Jun 10, 2019 183k views

1 Answer

Kewitschka · Answer 1 · 2019-06-16T06:37:10+0000

We have two right triangles and three different rectangles.

The formula of an area of a right triangle:

A_T=(1)/(2)l_1l_2

l₁, l₂ - legs

We have l₁ = 20cm and l₂ = 21cm. Substitute:

$A_T=(1)/(2)(20)(21)=(10)(21)=210\ cm^2$

The formula of an area of a rectangle:

A_R=lw

l - length

w - width

We have:

rectangle #1: l = 22cm, w = 29cm

$A_(R1)=(22)(29)=638\ cm^2$

rectangle #2: l = 22cm, w = 21cm

$A_(R2)=(22)(21)=462\ cm^2$

rectangle #3: l = 22cm, w = 20cm

$A_(R3)=(22)(20)=440\ cm^2$

The total Surface Area of the triangular prism:

$S.A.=2A_T+A_(R1)+A_(R2)+A_(R3)\\\\S.A.=2\cdot210+638+462+440=1960\ cm^2$