Please answer my question. It is optional maths?

The vertices of ▲ A(2,-3), B(5,-5) and C(3,0). ▲ ABC is translated through vector (2,-3)' to get the image ▲A'B'C' and ▲A'B'C is rotated through quarter turn in anticlockwise direction about origin to get image ▲A"B''C''. Find the coordinates of the vertices of ▲A'B'C and ▲A''B''C'' and plot it in graph?

1 Answer
Mar 23, 2018

The vertices of ∆A''B''C'' are
A''(9, 4), B''(8, 7) and C''(3, 5).

Explanation:

Warning : Long answer

The vertices of ∆ABC are A(2, -3), B(5, -5) and C(3, 0).

Translation vector = (2, -3)

When the translation vector, T =(a, b) then,

P(x, y) ⟶ P'(x+a, y+b)

A(2, -3) ⟶ A'{2 + 2, -3 + (-3)} = A'(4, -9)
B(5, -5) ⟶ B'{5 + 2, -5 + (-3)} = B'(7, -8)
C(3, 0) ⟶ C'{3 +2, 0 + (-3)} = C'(5, -3)

The vertices of ∆A'B'C' are A'(4, -9), B'(7, -8) and C'(5, -3)

Under rotation about origin through quarter turn in anticlockwise direction (+90^0),

P(x, y) → P'(-y,x)

A'(4, -9) → A''(9, 4)
B'(7, -8) → B''(8, 7)
C'(5, -3) → C''(3, 5)
The vertices of ∆A''B''C'' are
A''(9, 4), B''(8, 7) and C''(3, 5).

enter image source here

Here, yellow colored triangle represents ∆ABC with vertices A(2, -3), B(5, -5) and C(3, 0).

Red colored triangle represents ∆A'B'C' with vertices A'(4, -9), B'(7, -8) and C'(5, -3).

Blue colored triangle represents ∆A''B''C'' with vertices A''(9, 4), B''(8, 7) and C''(3, 5).

Hope it helps :)