Question

XYZ is an isosceles triangle inscribed I a circle, center O. XY=XZ= 20 and YZ=18. Calculate to 3.s.f.

a) the altitude of ∆XYZ
b) the diameter of the circle

Answer 1

Answer: 17.9

Explanation:

Using Heron's formula:

Area of a triangle is given by:

√s(s-a)(s-b)(s-c)

Where a, b and c ara sides of the triangle and

S = (a+b+c) / 2

In the question above sides are :

XY=XZ= 20 and YZ=18

S = (20 + 20 + 18) / 2 = 58/2 = 29

Area = √29(29-20)(29-20)(29-18)

Area = √29(9)(9)(11)

Area = √25839

Area = 160.74513

Altitude = height(h)

Area = 0.5 × base × height

Base = yz = 18

160.74513 = 0.5 × 18 × h

160.74513 = 9 × h

h = 160.74513 / 9

h = 17.9 (3 s.f)