Question

find the area.
a =? cm²
a△ = ½b·h

Explanation:

Step1: Substitute the values into the formula

The formula for the area of a triangle is \(A_{\triangle}=\frac{1}{2}b\cdot h\). Here, \(b = 21\) cm and \(h = 8\) cm.
So, \(A_{\triangle}=\frac{1}{2}\times21\times8\).

Step2: Calculate the product

First, calculate \(21\times8 = 168\).
Then, \(\frac{1}{2}\times168\).

Step3: Simplify the expression

\(\frac{168}{2}=84\).

Answer:

\(84\)