Question

An equilateral triangle with side length 19 cm is shown in the diagram, work out the height of the triangle. Give your answer rounded to 1 DP. The diagram is not drawn accurately.

Answer 1

h = 16.5

Explanation:

Remark

The formula below really is the Pytharagan formula disguised.

h^2 = hypotenuse (side)^2 - (1/2 side)^2

Givens

side = 19 cm

Solution

h^2 = 19^2 - (1/2*19)^2 Substitute given into formula

h^2 = 361 - (9.5)^2 square 9.5

h^2 = 361 - 90.25 Subtract

h^2 = 270.75 Take the square root of both sides

√h^2 = √270.75

Answer: h = 16.5