Answer:
a = 10 cm
Step-by-step explanation:
Area of triangle, A = 51 cm²
base, b = 10.2 cm
Let height of triangle be a cm
Formula:-
[tex]A=\dfrac{1}{2}\times a\times b[/tex]
[tex]51=\dfrac{1}{2}\times a\times 10.2[/tex]
[tex]a=\dfrac{51\times 2}{10.2}[/tex]
[tex]a=10[/tex]
hence, the missing length is 10 cm
