Looking for geometry proof help on a problem with parallelograms and an isosceles triangle

Step-by-step explanation:

30. Given: rectangles QRST and RKST

     Prove: ΔQSK is isosceles

An isosceles triangle is a triangle which has two sides and two angles to be equal.

Thus,

From rectangle QRST, the diagonals of rectangles are similar.

i.e RT ≅ QS (diagonal property)

Also, RT ≅ SK (opposite sides of rectangle RKST)

Thus,

RT ≅ QS  ≅ SK

Therefore,

ΔQSK is an isosceles triangle.

31. Given: Rectangles QRST, RKST and JQST

     Prove: JT ≅ KS

From rectangle QRST, the diagonals of rectangles are similar.

i.e RT ≅ QS (diagonal property)

But,

JT // QS and RT // KS

Thus,

JT ≅ QS (opposite sides of rectangle JQST)

also,

RT ≅ KS (opposite sides of rectangle RKST)

So that,

JT ≅ QS ≅ RT ≅ KS

Therefore,

JT ≅ KS

4x and 6y

im not sure though

36 girls

step-by-step explanation:

the 48 boys is 4 parts of the ratio

divide 48 by 4 to obtain one part of the ratio

= 12 ← 1 part of the ratio

3 parts = 3 × 12 = 36 ← number of girls