# 7 28 28 triangle

### Acute isosceles triangle.

Sides: a = 7   b = 28   c = 28

Area: T = 97.23113606816
Perimeter: p = 63
Semiperimeter: s = 31.5

Angle ∠ A = α = 14.36215115629° = 14°21'41″ = 0.25106556623 rad
Angle ∠ B = β = 82.81992442185° = 82°49'9″ = 1.44554684956 rad
Angle ∠ C = γ = 82.81992442185° = 82°49'9″ = 1.44554684956 rad

Height: ha = 27.78803887662
Height: hb = 6.94550971915
Height: hc = 6.94550971915

Median: ma = 27.78803887662
Median: mb = 14.84992424049
Median: mc = 14.84992424049

Inradius: r = 3.08767098629
Circumradius: R = 14.1110673659

Vertex coordinates: A[28; 0] B[0; 0] C[0.875; 6.94550971915]
Centroid: CG[9.625; 2.31550323972]
Coordinates of the circumscribed circle: U[14; 1.76438342074]
Coordinates of the inscribed circle: I[3.5; 3.08767098629]

Exterior(or external, outer) angles of the triangle:
∠ A' = α' = 165.6388488437° = 165°38'19″ = 0.25106556623 rad
∠ B' = β' = 97.18107557815° = 97°10'51″ = 1.44554684956 rad
∠ C' = γ' = 97.18107557815° = 97°10'51″ = 1.44554684956 rad

# 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 #### Look also our friend's collection of math examples and problems:

See more informations about triangles or more information about solving triangles.