# Geometry

We were learning about geometry and most specifically about transformation, Congruence, Similarity, and Right triangle & trigonometry. So we are using Khan Academy to help our guild through this topic because the in the textbook it doesn’t demonstrate and give examples much. For each level, we reach we got 4 points and there is 6 level which is mastering it but the teacher expected us to get to level 5 and we will have 20 points. However, if we have any questions we can screenshot it, and then we will go over it in class together. By doing this it allows us to go at our own pass and not rushing through to gets point but actually understanding it. Moreover, it gives students the opportunities to take more responsibility and show that they use their time wisely.

Transformation

• Rigid: maintain and produce congruent shape
• Translation: vertical and horizontal shifts
• Rotation: it’s rotate in a certain degree.

270 / -90 degree = x,y   y,-x

-270 / 90 degree = x,y  -y,x

180/-180 degree = x,y  -x,-y

• Reflection: line of reflection and it’s a mirrored image

• Dilation: It have the similar shape but different size and it’s scaleable and it’s angle is the same.

Congruence – equal size and shape Similarity – same shape in term of ratio Right triangle & trigonometry

Sin = Opposite over Hypotenuse

Cos = Adjacent over hypotenuse

Tan = Opposite over Adjacent

Law of sin = > sin (a) over a = sin (b) over b = sin (c) over c

• If you have 2 angle and 1 length use it to find another length
• If you have 1 angle and 2 length use it to find another angle

Law of cos

=> a² = b²+c² * – 2bc cos(o)

=> b² = a²+c² * – 2ac cos(o)

=> c² = a²+b² * – 2ab cos(o)

• If you have 2 lengths and an angles use it to find another length
• If you have 3 lengths use it to find an angles
• a, b, c  representing the lengths