# 11 13 15 triangle

### Acute scalene triangle.

**Sides:**a = 11 b = 13 c = 15

**Area:**T = 69.62989271783

**Perimeter:**p = 39

**Semiperimeter:**s = 19.5

**Angle**∠ A = α = 45.57329959992° = 45°34'23″ = 0.79553988302 rad

**Angle**∠ B = β = 57.56435627878° = 57°33'49″ = 1.00546736998 rad

**Angle**∠ C = γ = 76.86334412131° = 76°51'48″ = 1.34215201236 rad

**Height:**h

_{a}= 12.66598049415

**Height:**h

_{b}= 10.71221426428

**Height:**h

_{c}= 9.28438569571

**Median:**m

_{a}= 12.91331715701

**Median:**m

_{b}= 11.4354596626

**Median:**m

_{c}= 9.42107218407

**Inradius:**r = 3.57107142143

**Circumradius:**R = 7.70215404622

**Vertex coordinates:**A[15; 0] B[0; 0] C[5.9; 9.28438569571]

**Centroid:**CG[6.96766666667; 3.09546189857]

**Coordinates of the circumscribed circle:**U[7.5; 1.7550350105]

**Coordinates of the inscribed circle:**I[6.5; 3.57107142143]

**Exterior(or external, outer) angles of the triangle:**

∠ A' = α' = 134.4277004001° = 134°25'37″ = 0.79553988302 rad

∠ B' = β' = 122.4366437212° = 122°26'11″ = 1.00546736998 rad

∠ C' = γ' = 103.1376558787° = 103°8'12″ = 1.34215201236 rad

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# How did we calculate this triangle?

Now we know the lengths of all three sides of the triangle and the triangle is uniquely determined. Next we calculate another its characteristics - same procedure as calculation of the triangle from the known three sides SSS.### 1. The triangle circumference is the sum of the lengths of its three sides

### 2. Semiperimeter of the triangle

### 3. The triangle area using Heron's formula

### 4. Calculate the heights of the triangle from its area.

### 5. Calculation of the inner angles of the triangle using a Law of Cosines

### 6. Inradius

### 7. Circumradius

### 8. Calculation of medians

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