Question

The area of a triangle is 21ft². If the height of the triangle is 7ft, how long is the base of the triangle? Please give your answer and explain how you found it.

Answer 1

b = 6ft

Explanation:

Area of a triangle = 1/2 x base x height

Given the area = 21ft^2

Height = 7ft

Base = ?

Using the above formula

21 = 1/2 x b x 7

21 = 7b/2

Cross multiply

7b = 21 x 2

7b = 42

Divide both sides by 7

7b/7 = 42/7

b = 6ft

The length of the base is 6ft

Answer 2

The answer is b = 6

Explanation:

Area of a triangle= 1/2 × b × h

A = 21, h = 7, b = ?

21 = 1/2 × b × 7 (multiplying through)

21 = 7b/2

Cross multiply

2 × 21 = 7b

42 = 7b

b = 42/7

b = 6