ACT Practice Questions — All Questions

A triangle has a base of 10 units and a height of 6 units. What is its area?

• a.30✓
• b.16
• c.15
• d.60

The area of a triangle is one half the base times the height: (1/2)(10)(6) = (1/2)(60) = 30 square units.

A right triangle has legs of length 6 and 8. What is the length of the hypotenuse?

• a.12
• b.48
• c.10✓
• d.14

By the Pythagorean theorem, the hypotenuse c satisfies c^2 = 6^2 + 8^2 = 36 + 64 = 100, so c = 10.

What is the area of a circle with radius 5, expressed in terms of pi?

• a.100π
• b.10π
• c.25π✓
• d.5π

The area of a circle is pi times the radius squared: π(5)^2 = 25π. The circumference (not asked here) would be 10π.

What is the sum of the interior angles of a regular pentagon?

• a.450°
• b.720°
• c.360°
• d.540°✓

The sum of interior angles of a polygon is (n - 2) * 180 degrees. For a pentagon, n = 5, so (5 - 2)(180) = 3(180) = 540 degrees.