Question

A triangular pyramid is formed from three right triangles as shown below.

Answer 1

ΔADC is a right angle triangle, we will use the Pythagorus Theorem to find the length CD.

Formula of the Pythagorus Theorem :  

⇒ a² + b² = c²

⇒ AD² + CD² = AC²

The value of AD is 54 and the value of AC is 90:

54² + CD² = 90²

Solve for CD:

54² + CD² = 90²

CD² = 90² - 54²

CD² = 5184

CD = √5184

CD = 72

ΔADC is also a right angle triangle, we will use the Pythagorus Theorem to find the length BD.

Formula of the Pythagorus Theorem :  

⇒ a² + b² = c²

⇒ BD² + CD² = BC²

The value of CD is 72 and the value of BC is 97:

BD² + 72² = 97²

Solve for BD:

BD² = 97² - 72²

BD² = 4225

BD = √4225

BD = 65

Answer: The length of BD is 65 units.