G3

Question 1

if an object x is made 1/20th of the size of object y, then what would be the ratio of object x to object y’s volume and area

What types of shapes can these be used for

Answer 1

the linear scale factor is 1:20, however this wouldn’t work for the volume and area, as they are both x^2 and x^3 respectively

therefore for area it would be
1^2 : 20^2

and volume it would be
1^3 : 20^3

THESE CAN ONLY BE USED FOR SIMILAR SHAPES (look out for SIMILAR in the exam)

Question 2

What are the methods to prove a triangle is congruent and explain each one

Answer 2

SSS:
If 2 triangles have 3 sides of the same length they are congruent

SAS:
If 2 triangles both have 2 sides the same length and they both make an angle of the same size they are congruent

ASA:
If we know both triangles have the same 2 angles with the same length side in between them then they are congruent

RHS:
If we have a right angle triangle, with the hypotenuse length and the length on another side then we know those 2 are congruent (if the length of hypotenuse and other side are equal)

Question 3

Vertically _____ angles are _____

Answer 3

opposite
equal

Question 4

If we know the area ratio of 2 shapes, and want to find their volume ratio to find the volume of one of those shapes wyd

Answer 4

square root it to get the length ratio, then cube that to get the volume

Question 5

Tips for 3d pythag

Answer 5

1) Always draw the triangle where the hypotenuse is the missing length

2) remember SOHCAHTOA as you will need to find out missing lengths using angles

3) Remember to use the inverse of SOHCAHTOA to find missing angles if the question asks for it