Answer:
Step-by-step explanation:
It can be convenient to compute the length of the hypotenuse of this triangle (AC). The Pythagorean theorem tells you ...
AC^2 = AB^2 + CB^2
AC^2 = 4^2 + 3^2 = 16 + 9 = 25
AC = √25 = 5
The altitude divides ∆ABC into similar triangles ∆AHB and ∆BHC. The scale factor for ∆AHB is ...
scale factor ∆ABC to ∆AHB = AB/AC = 4/5 = 0.8
And the scale factor to ∆BHC is ...
scale factor ∆ABC to ∆BHC = BC/AC = 3/5 = 0.6
Then the side AH is 0.8·AB = 0.8·4 = 3.2
And the side CH is 0.6·BC = 0.6·3 = 1.8
These two side lengths should add to the length AC = 5, and they do.
The remaining side BH can be found from either scale factor:
BH = AB·0.6 = BC·0.8 = 4·0.6 = 3·0.8 = 2.4
_____
The sides of interest are ...
AH = 3.2
CH = 1.8
BH = 2.4
Answer:
<em>119.0 cm²</em>
Step-by-step explanation:
What is surface area
It is the area of the outside part of anything. Surface area is also called total surface area.
As we can see from the pyramid, it has a square base. How do I know that it is a square base, is by seeing the dimensions of the base, which are 6.4 cm by 6.4 cm in this pyramid. And we already know from basic Geometry that a square has 4 equal sides. So we call it a square pyramid.
So to find the total surface area of this square pyramid, we need the area of the 4 triangular faces and the area of the square base.
So t.s.a of the pyramid = 4 × Area of each triangular face + Area of the square base.
So, total surface area = Area of square base + Area of the four triangular faces.
<em>total surface area</em> = (<em>length²) + (</em>4 ×
× <em>base × height)</em>
<em> t</em><em>otal surface area =</em><em> </em>(6.4 × 6.4) + (4 ×
× 6.4 × 6.1)
<em>total surface area = 40.96 + 78.08</em>
<em> total surface area = 119.04 cm² ≈ 119.0 cm² (to the nearest tenth) (Answer)</em>