Day 4 — Pythagorean Theorem & Transformations

8th Grade STAAR Math Review | TEKS 8.7(C) & 8.10(A) | Independent Practice

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🖩 PYTHAGOREAN THEOREM (on your reference chart!): a² + b² = c²  |  DESMOS: Line 1: a² + b² ~ c² → Define known values → Leave unknown BLANK  |  c = hypotenuse (LONGEST side)
TRANSFORMATIONS: Translate: (x+a, y+b)  |  Reflect x-axis: (x, −y)  |  Reflect y-axis: (−x, y)  |  Rotate 90° CW: (y, −x)
Part A: Pythagorean Theorem with Desmos (Problems 1–5)
1 A TV screen at AT&T Stadium is 40 inches wide and 30 inches tall. Find the diagonal.
a = (width)
b = (height)
c = (solving for)
Line 1: a² + b² ~ c²
Line 2: a = ___
Line 3: b = ___
Line 4: c =   (leave ________)
Answer: c = inches (the diagonal)
2 A ladder is 17 ft long and its base is 8 ft from a Dallas building. How high does it reach? (Find a LEG!)
a = (base)
b = (solving for: height)
c = (ladder = hypotenuse)
Line 1: a² + b² ~ c²
Line 2: a = ___
Line 3: b =   (leave ________)
Line 4: c = ___
Answer: b = ft
3 Klyde Warren Park is 200 ft long and 80 ft wide. Find the diagonal path across it.
a =
b =
c = (diagonal = hypotenuse)
Line 1: a² + b² ~ c²
Line 2: a = ___
Line 3: b = ___
Line 4: c =   (leave blank)
Answer: c ≈ ft
4 A ramp is 15 ft long and 9 ft high. How far is the base of the ramp from the wall?
a = (solving for: base)
b = (height)
c = (ramp = hypotenuse)
Line 1: _______________
Line 2: a =   (leave ___)
Line 3: b = ___
Line 4: c = ___
Answer: a = ft
5 ⭐ A rope goes from the top of a 12 ft pole to a point on the ground 5 ft from the base. How long is the rope?
a =
b =
c = (which are you solving for?)
Type all 4 Desmos lines on your own:
Line 1: _______________
Line 2: _______________
Line 3: _______________
Line 4: _______________
Answer: = ft
Part B: Transformations (Problems 6–10)
6 Translate triangle A(1,2), B(4,2), C(1,5) → 3 units RIGHT and 2 units UP.
Rule: (x + 3, y + 2)
OriginalRule AppliedNew Point
A(1, 2)(1+3, 2+2)A'(, )
B(4, 2)(4+3, 2+2)B'(, )
C(1, 5)(1+3, 5+2)C'(, )
7 Reflect triangle A(1,2), B(4,2), C(1,5) across the y-axis.
Rule: (−x, y)
OriginalRule AppliedNew Point
A(1, 2)(−1, 2)A'(, )
B(4, 2)(, )B'(, )
C(1, 5)(, )C'(, )
8 Reflect point P(3, −4) across the x-axis.
Rule for x-axis: (x, −y)
P(3, −4) → P'(, )
Show work: (3, −(−4)) = (3, ___)
9 Rotate triangle D(2,1), E(5,1), F(2,4) by 90° clockwise.
Rule: (y, −x)
OriginalRule AppliedNew Point
D(2, 1)(1, −2)D'(, )
E(5, 1)(, )E'(, )
F(2, 4)(, )F'(, )
10 ⭐ CHALLENGE: Shape ABCD: A(1,1), B(3,1), C(3,4), D(1,4). First translate 2 RIGHT, then reflect across the x-axis.
Step 1 Rule: (x+2, y)   |   Step 2 Rule: (x, −y)
OriginalAfter TranslateAfter Reflect x-axis
A(1, 1)(, )A''(, )
B(3, 1)(, )B''(, )
C(3, 4)(, )C''(, )
D(1, 4)(, )D''(, )
✅ Self-Check Before You Turn This In:
☐ Did I label a, b, c for every Pythagorean problem? (c = hypotenuse = LONGEST)
☐ Did I leave the unknown variable BLANK in Desmos?
☐ Did I write the transformation rule before applying it?
☐ Did I apply the rule to EVERY point (not just one)?