Question

1. Find the coordinates of the centroid of the triangle with the given vertices.

A(2,3), B(8, 1), C(5,7)



The centroid is ( , )

Answer 1

46940064

Explanation:

1)

The angle of inclination is the angle between the horizontal and the ramp.

Using the sine ratio in the right triangle formed by the ground and the ramp

let x be the angle of inclination, then

sinx = \frac{opposite}{hypotenuse}

hypotenuse

opposite

= \frac{0.7}{4.2}

4.2

0.7

, then

x = sin^{-1}sin

−1

(\frac{0.7}{4.2}

4.2

0.7

) ≈ 10° ( to the nearest degree )

(2)

Again there is a right triangle between the ground and the vertical height of the kite, with hypotenuse being length of string.

let y be the height of the kite and x the horizontal distance, then

sin27° = \frac{opposite}{hypotenuse}

hypotenuse

opposite

= \frac{y}{176}

176

y

( multiply both sides by 176 )

176 × sin27° = y , then

y ≈ 80m ( to the nearest metre ) ← height of kite

and

cos27° = \frac{adjacent}{hypotenuse}

hypotenuse

adjacent

= \frac{x}{176}

176

x

( multiply both sides by 176 )

176 × cos27° = x , then

x ≈ 157m ( to the nearest metre ) ← horizontal distance

Answer 2

9514 1404 393

Answer:

(5, 3 2/3)

Explanation:

The centroid is the average of the vertex coordinates:

(A +B +C)/3 = ((2, 3) +(8, 1) +(5, 7))/3 = (2+8+5, 3+1+7)/3 = (5, 3 2/3)