80*4=320-(71+80+86)=83 So 83 needs to be added.
Answer:
Cross sections perpendicular to the base and through the vertex will be triangles. Below, you can see a plane cutting through the pyramid, part of the pyramid removed, and the cross section. You could also take a slice parallel to the base. Cross sections parallel to the base will be hexagons.
Step-by-step explanation:
Answer:
∠a = 45°
Step-by-step explanation:
We are told that △abc and △xyz are congruent.
Thus;
∠a = ∠x
∠b = ∠y
∠c = ∠z
We are given;
∠y = 90°
Thus, ∠b = 90°
Now,we are told that ∠a is one half the size of ∠b.
Thus; ∠a = ½ × ∠b
∠a = ½ × 90
∠a = 45°
18 x
--- = ----
5 100
18×100 = 5×x
1800 = 5x
------- ----
5 5
360 = x
Hope this helps!!!
