A decagon has 10 sides and an octagon has 8. 5*8 + 5*10 = 90 sides
There are 8 triangles in a decagon
There are ten sides in a decagon and three sides in a triangle. So in 3 decagons and 5 triangles there are 3*10 + 5*3 = 30 + 15 = 45 sides altogether.
10 triangles make a decagon
A decagon can have eight or more triangles - up to infinitely many.
An octagon has 8 sides. A decagon has 10. So 3*8+10 = 34 sides
A decagon has ten sides and an octagon has eight, so in 3 decagons and 5 octagons there are (3*10)+(5*8) = 30 + 40 = 70 sides altogether.
A decagon has 10 sides and an octagon has 8. 5*8 + 5*10 = 90 sides
There are 8 triangles in a decagon
A decagon has ten sides and a triangle has three, so 5 decagons and 4 triangles have (5*10)+(4*3) = 62 sides altogether.
A decagon has ten sides, a heptagon seven, and an octagon eight. So in 4 decagons, 4 heptagons, and 3 octagons there are 4*10 + 4*7 + 3*8 = 40 + 28 + 24 = 92 sides altogether.
There are 8 triangles inside a 10 sided decagon
There are ten sides in a decagon and three sides in a triangle. So in 3 decagons and 5 triangles there are 3*10 + 5*3 = 30 + 15 = 45 sides altogether.
10 triangles make a decagon
A decagon can have eight or more triangles - up to infinitely many.
They add up to (1*10)+(4*4)+(3*5) = 41 sides altogether
8 triangles will fit inside a 10 sided decagon