Spectrum Math Grade 7 Chapter 5 Lesson 10 Answer Key Area: Triangles

This handy Spectrum Math Grade 7 Answer Key Chapter 5 Lesson 5.10 Area: Triangles provides detailed answers for the workbook questions

Spectrum Math Grade 7 Chapter 5 Lesson 5.10 Area: Triangles Answers Key

To find the area of a triangle, find \(\frac{1}{2}\) the product of the measure of its base and its height.
A = \(\frac{1}{2}\) × b × h

b = 6 in. and h = 8 in. Find A.
A = \(\frac{1}{2}\) × b × h
A = \(\frac{1}{2}\) × 6 × 8
A = 24 in.²

The height is the distance from the base to the highest point on the triangle using a line perpendicular to the base.

Find the area of each triangle.

Question 1.
a.

area = _____________ m²
Answer:
area = 210 m²

Explanation:
A = \(\frac{1}{2}\) × b × h
Given,
b = 21 m. and h = 20m
A = \(\frac{1}{2}\) × b × h
A = \(\frac{1}{2}\) × 21 × 20
A = \(\frac{1}{2}\) x 420
A = 210 m.²

b.

area = ______________ ft.²
Answer:
area = 14 ft.²

Explanation:
A = \(\frac{1}{2}\) × b × h
Given,
b = 7ft. and h = 4ft
A = \(\frac{1}{2}\) × b × h
A = \(\frac{1}{2}\) × 7 × 4
A = \(\frac{1}{2}\) x 28
A = 14 ft.²

c.

area = ______________ in.²
Answer:
area = 199.5 in.²

Explanation:
A = \(\frac{1}{2}\) × b × h
Given,
b = 19 in. and h = 21 in
A = \(\frac{1}{2}\) × b × h
A = \(\frac{1}{2}\) × 19 × 21
A = \(\frac{1}{2}\) x 399
A = 199.5 in.²

Question 2.
a.

area = _______________ cm²
Answer:
area = 270 cm²

Explanation:
A = \(\frac{1}{2}\) × b × h
Given,
b = 36 cm. and h = 15 cm
A = \(\frac{1}{2}\) × b × h
A = \(\frac{1}{2}\) × 36 × 15
A = \(\frac{1}{2}\) x 540
A = 270 cm.²

b.

area = _______________ m²
Answer:
area = 162 m²

Explanation:
A = \(\frac{1}{2}\) × b × h
Given,
b = 18 m. and h = 18 m
A = \(\frac{1}{2}\) × b × h
A = \(\frac{1}{2}\) × 18 × 18
A = \(\frac{1}{2}\) x 324
A = 162 m.²

c.

area = _______________ cm²
Answer:
area = 272 cm²

Explanation:
A = \(\frac{1}{2}\) × b × h
Given,
b = 32 cm. and h = 17 cm
A = \(\frac{1}{2}\) × b × h
A = \(\frac{1}{2}\) × 32 × 17
A = \(\frac{1}{2}\) x 544
A = 272 cm.²

Question 3.
a.

area = ______________ ft.²
Answer:
area = 348 ft.²

Explanation:
A = \(\frac{1}{2}\) × b × h
Given,
b = 29 ft. and h = 24 ft.
A = \(\frac{1}{2}\) × b × h
A = \(\frac{1}{2}\) × 29 × 24
A = \(\frac{1}{2}\) x 696
A = 348 ft.²

b.

area = _______________ in.²
Answer:
area = 230 in.²

Explanation:
A = \(\frac{1}{2}\) × b × h
Given,
b = 23 in. and h = 20 in
A = \(\frac{1}{2}\) × b × h
A = \(\frac{1}{2}\) × 23 × 20
A = \(\frac{1}{2}\) x 460
A = 230 in.²

c.

area = _______________ cm²
Answer:
area = 312.5 cm²

Explanation:
A = \(\frac{1}{2}\) × b × h
Given,
b = 25 cm. and h = 25 cm
A = \(\frac{1}{2}\) × b × h
A = \(\frac{1}{2}\) × 25 × 25
A = \(\frac{1}{2}\) x 625
A = 312.5 cm.²