# Sum of inner angles

Prove that the sum of all inner angles of any convex n-angle equals (n-2) . 180 degrees.

**Result****Leave us a comment of example and its solution (i.e. if it is still somewhat unclear...):**

**Showing 0 comments:**

**Be the first to comment!**

#### To solve this example are needed these knowledge from mathematics:

## Next similar examples:

- n-gon

Gabo draw n-gon, which angles are consecutive members of an arithmetic sequence. The smallest angle is 70° biggest 170°. How many sides have Gabo's n-gon? - Pentagon

Within a regular pentagon ABCDE point P is such that the triangle is equilateral ABP. How big is the angle BCP? Make a sketch. - 4side pyramid

Calculate the volume and surface of 4 side regular pyramid whose base edge is 4 cm long. The angle from the plane of the side wall and base plane is 60 degrees. - Pentagonal pyramid

Calculate the volume of a regular 5-side (pentaprism) pyramid ABCDEV; if |AB| = 7.7 cm and a plane ABV, ABC has angle 37 degrees. - Kites

Boys run kite on a cable of 68 meters long. What is the kite altitude, if the angle from the horizontal plane is 72°? - n-gon II

What is the side length of the regular 5-gon circumscribed circle of radius 11 cm? - n-gon

What is the side length of the regular 5-gon inscribed in a circle of radius 12 cm? - Hexagon - MO

The picture shows the ABCD square, the EFGD square and the HIJD rectangle. Points J and G lie on the side CD and is true |DJ| - Tetrahedral pyramid

What is the surface of a regular tetrahedral (four-sided) pyramid if the base edge a=7 and height v=6? - Regular 5-gon

Calculate area of the regular pentagon with side 7 cm. - Pentagon

Calculate the area of regular pentagon, which diagonal is u=17. - Tower

The top of the tower is a regular hexagonal pyramid with base edge 8 meters long and a height 5 meters. How many m^{2}of sheet is required to cover the top of the tower if we count 8% of the sheet waste? - Octagon

We have a square with side 84 cm. We cut the corners to make his octagon. What will be the side of the octagon? - Hexagon

There is regular hexagon ABCDEF. If area of the triangle ABC is 22, what is area of the hexagon ABCDEF? I do not know how to solve it simply.... - Hexagon A

Calculate area of regular hexagon inscribed in circle with radius r=9 cm. - Octahedron - sum

On each wall of a regular octahedron is written one of the numbers 1, 2, 3, 4, 5, 6, 7 and 8, wherein on different sides are different numbers. For each wall John make the sum of the numbers written of three adjacent walls. Thus got eight sums, which also. - Hexagonal pyramid

Calculate the volume and the surface of a regular hexagonal pyramid with a base edge length 3 cm and a height 5 cm.