# PLOT ME FIRST: An Activity Involving Triangles on Cartesian Plane

Deanne is a ninth grade student who's currently answering her departmental test in Mathematics. She's having a hard time answering the last part of her exam for 30-points stating:
Plot four triangles on the Cartesian Plane, joining three different points for each of the three-sided polygon(each point is provided with x and y coordinates). Afterwards, determine which pair of triangles are similar and congruent. Lastly, solve for the area of the congruent triangles.
∆ABC
coordinates:
A (-10,-5)
B (-10,-15)
C (-5,-15)
∆JKL
coordinates:
J (-20,-20)
K (0,-10)
L (0, -30)
∆DEF
coordinates:
D (5, -5)
E (0,-5)
F (5,5)
∆GHI
coordinates:
G (-10,0)
H (0,0)
I (-5,10)
On behalf of Deanne who is in need of assistance, accomplish the last part of her exam by showing your solution.
LEARNING COMPETENCIES:
To be able to accomplish the task, the learner should:
•know how to plot points on the Cartesian Plane and be familiar with the x and y coordinates in order to construct triangle utilizing the points provided
•be familiar with the concept of congruent and similar triangles
•know how to solve the area of a triangle with given base and height
ANSWERS AND DISCUSSIONS:
CONGRUENT TRIANGLES:
∆ABC ∆DEF
•The two triangles have exactly the same dimensions and angles.
SIMILAR TRIANGLES:
∆GHI ∆JKL
•The two triangles have dimensions and angles that are with the same proportion.
AREA OF THE CONGRUENT TRIANGLES:
Using the formula:
Area=1/2 bh
*base=5 units
*height=10 units
=1/2 (5)(10)
=25 square units
REFERENCES:
•(n.d.). Retrieved October 01, 2020, from https://www.varsitytutors.com/hotmath/hotmath_help/topics/area-of-triangle
•Congruent and Similar Triangles. (n.d.). Retrieved October 01, 2020, from https://brilliant.org/wiki/congruent-and-similar-triangles//u/hjelm
•(n.d.).Triangle Construction. Retrieved October 01, 2020, from https://www.geogebra.org/m/uvxyYrhY

## New Resources

## Discover Resources

Download our apps here: