Note necessary facts about isosceles triangle ABC:
- The median CD drawn to the base AB is also an altitude to tha base in isosceles triangle (CD⊥AB). This gives you that triangles ACD and BCD are congruent right triangles with hypotenuses AC and BC, respectively.
- The legs AB and BC of isosceles triangle ABC are congruent, AC=BC.
- Angles at the base AB are congruent, m∠A=m∠B=30°.
1. Consider right triangle ACD. The adjacent angle to the leg AD is 30°, so the hypotenuse AC is twice the opposite leg CD to the angle A.
AC=2CD.
2. Consider right triangle BCD. The adjacent angle to the leg BD is 30°, so the hypotenuse BC is twice the opposite leg CD to the angle B.
BC=2CD.
3. Find the perimeters of triangles ACD, BCD and ABC:



4. If sum of the perimeters of △ACD and △BCD is 20 cm more than the perimeter of △ABC, then

5. Since AC=BC=2CD, then the legs AC and BC of isosceles triangles have length 20 cm.
Answer: 20 cm.
Answer:

Step-by-step explanation:
Given




Required
Determine the new coordinate of J
From rules of rotation,
When a point (x,y) is rotated 270 degrees CCW;
The new point becomes (y,-x)
Considering point J

This means

Where
and 
Using the above rotation rule of

The coordinates of J' becomes

a, b, c - side lengths (a ≤ b ≤ c)
If
, then is Obtuse triangle.
If
, then is Right triangle.
If
, then Acute triangle.

Check to see if the sum of the first two sides is greater than the third.

, therefore is Scalene triangle.

It's Obtuse triangle.
Actual question is "<span>Jeremy had 3/4 of a submarine sandwich and gave his friend 1/3 of it. What fraction of the sandwich did the friend receive?"
Solution:
1/3 of 3/4 of a submarine sandwich = 1/3x3/4 = 3/12 = 1/4
so jermy gave 1/4 of the submarine sandwich to his friend. </span>