You have the area of a triangle by this formula;

A = 1/2 × base × height.

and you just plug in which numbers are the base and height to find the area of it.

hope this helps, God bless!

7 0

3 years ago

Read 2 more answers

What is the area of a trapezoid ABCD with bases AB and CD ,

Mrrafil [7]

check the picture below on the top side.

we know that x = 4 = b, therefore, using the 30-60-90 rule, h = 4√3, and DC = 4+8+4 = 16.

$\bf \textit{area of a trapezoid}\\\\
A=\cfrac{h(a+b)}{2}~~
\begin{cases}
a,b=\stackrel{bases}{parallel~sides}\\
h=height\\[-0.5em]
\hrulefill\\
a=8\\
b=\stackrel{DC}{16}\\
h=4\sqrt{3}
\end{cases}\implies A=\cfrac{4\sqrt{3}(8+16)}{2}
\\\\\\
A=2\sqrt{3}(24)\implies \boxed{A=48\sqrt{3}}$

now, check the picture below on the bottom side.

since we know x = 9, then b = 9, therefore DC = 9+6+9 = 24, and h = b = 9.

$\bf \textit{area of a trapezoid}\\\\
A=\cfrac{h(a+b)}{2}~~
\begin{cases}
a,b=\stackrel{bases}{parallel~sides}\\
h=height\\[-0.5em]
\hrulefill\\
a=6\\
b=\stackrel{DC}{24}\\
h=9
\end{cases}\implies A=\cfrac{9(6+24)}{2}
\\\\\\
A=\cfrac{9(30)}{2}\implies \boxed{A=135}$

7 0

3 years ago

The first four terms

sweet [91]

An1 = 3n^2 -7 = 3(1)^2 -7 = 3(1)-7 = -4

an2 = 3n^2 -7 = 3(2)^2 -7 = 3(4)-7 = 5

an3 = 3n^2 -7 = 3(3)^2 -7 = 3(9)-7 = 20

an4 = 3n^2 -7 = 3(4)^2 -7 = 3(16)-7 = 41

8 0

3 years ago